diff --git a/src/App.vue b/src/App.vue
index f92b4b7..991ac28 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -5,5 +5,5 @@
 <style scoped></style>
 
 <script setup>
-import { RouterLink, RouterView } from "vue-router";
+import { RouterView } from "vue-router";
 </script>
diff --git a/src/components/Navbar.vue b/src/components/Navbar.vue
index 7ace95c..50b6236 100644
--- a/src/components/Navbar.vue
+++ b/src/components/Navbar.vue
@@ -2,7 +2,7 @@
   <nav class="bg-neutral-700">
     <div class="mx-auto px-4" :class="[showNavbarBreadcrumb? 'min-h-12': 'h-12']">
       <div class="flex justify-between items-center flex-wrap" v-show="showNavbarBreadcrumb">
-        <div class="flex flex-1 items-center">
+        <div id="nav_bar" class="flex flex-1 items-center">
           <!-- 回 Files 頁 -->
           <router-link to="/files" class="mr-4" v-if="showIcon" id="backPage">
             <span class="material-symbols-outlined text-neutral-10 !leading-loose">
@@ -14,7 +14,10 @@
             <h2 v-else class="mr-14 py-3 text-2xl font-black text-neutral-10">FILES</h2>
           </div>
           <ul class="flex justify-center items-center space-x-4 text-xl font-semibold text-neutral-300 cursor-pointer">
-            <li @click="switchNavItem($event, item)" v-for="(item, index) in navViewData[navViewName]" :key="index" :class="{'active': isActive === item}">{{ item }}</li>
+            <li @click="switchNavItem($event, item)" v-for="(item, index) in navViewData[navViewName]"
+              :key="index" :class="{'active': activePage === item}">
+                {{ item }}
+            </li>
           </ul>
         </div>
         <!-- Files Page: Search and Upload -->
@@ -45,7 +48,10 @@
         <!-- Other Page: Save and Download -->
         <!-- Save 有 data 跳重新命名，沒有 data 跳要不要儲存，沒有動都不跳 -->
         <div v-else class="space-x-4">
-          <button class="btn btn-sm" :class="[ disabledSave ? 'btn-disable' : 'btn-neutral']" :disabled="disabledSave" @click="saveModal">Save</button>
+          <button class="btn btn-sm" :class="[ disabledSave ? 'btn-disable' : 'btn-neutral']"
+          :disabled="disabledSave" @click="saveModal">
+            Save
+          </button>
           <!-- <button class="btn btn-sm btn-neutral">Download</button> -->
         </div>
       </div>
@@ -53,10 +59,11 @@
   </nav>
 </template>
 <script>
-import { storeToRefs } from 'pinia';
+import { storeToRefs, mapState, mapActions, } from 'pinia';
 import filesStore from '@/stores/files.js';
 import AllMapDataStore from '@/stores/allMapData.js';
 import ConformanceStore from '@/stores/conformance.js';
+import PageAdminStore from '@/stores/pageAdmin.js';
 import IconSearch from '@/components/icons/IconSearch.vue';
 import IconSetting from '@/components/icons/IconSetting.vue';
 import { saveFilter, savedSuccessfully, saveConformance } from '@/module/alertModal.js';
@@ -68,9 +75,19 @@ export default {
     const allMapDataStore = AllMapDataStore();
     const conformanceStore = ConformanceStore();
     const { logId, tempFilterId, createFilterId, filterName, postRuleData, isUpdataFilter } = storeToRefs(allMapDataStore);
-    const { conformanceRuleData, conformanceLogId, conformanceFilterId, conformanceLogTempCheckId, conformanceFilterTempCheckId, conformanceLogCreateCheckId, conformanceFilterCreateCheckId, isUpdataConformance, conformanceFileName } = storeToRefs(conformanceStore);
+    const { conformanceRuleData, conformanceLogId, conformanceFilterId,
+      conformanceLogTempCheckId, conformanceFilterTempCheckId, 
+      conformanceLogCreateCheckId, conformanceFilterCreateCheckId,
+      isUpdataConformance, conformanceFileName
+    } = storeToRefs(conformanceStore);
 
-    return { store, allMapDataStore, logId, tempFilterId, createFilterId, filterName, postRuleData, isUpdataFilter, conformanceStore, conformanceRuleData, conformanceLogId, conformanceFilterId, conformanceLogTempCheckId, conformanceFilterTempCheckId, conformanceLogCreateCheckId, conformanceFilterCreateCheckId, isUpdataConformance, conformanceFileName }
+    return {
+      store, allMapDataStore, logId, tempFilterId, createFilterId,
+      filterName, postRuleData, isUpdataFilter, conformanceStore, conformanceRuleData,
+      conformanceLogId, conformanceFilterId, conformanceLogTempCheckId,
+      conformanceFilterTempCheckId, conformanceLogCreateCheckId,
+      conformanceFilterCreateCheckId, isUpdataConformance, conformanceFileName,
+    };
   },
   components: {
     IconSearch,
@@ -90,7 +107,6 @@ export default {
         COMPARE: ['DASHBOARD']
       },
       navViewName: 'FILES',
-      isActive: null,
       uploadModal: false,
     };
   },
@@ -113,8 +129,9 @@ export default {
       return result;
     },
     noShowSaveButton: function() {
-      return this.navViewName === 'UPLOAD' || this.navViewName === 'COMPARE' || this.isActive === 'PERFORMANCE' ? true : false;
-    }
+      return this.navViewName === 'UPLOAD' || this.navViewName === 'COMPARE' || this.activePage === 'PERFORMANCE' ? true : false;
+    },
+    ...mapState(PageAdminStore, ['activePage', 'pendingActivePage']),
   },
   watch: {
     '$route':'getNavViewName',
@@ -136,18 +153,20 @@ export default {
       let type;
       let fileId;
       let isCheckPage;
+      const navItemCandidate = event.target.innerText;
+
+      this.setPendingActivePage(navItemCandidate);
 
-      this.isActive = event.target.innerText;
       switch (this.navViewName) {
         case 'FILES':
-          this.store.filesTag = event.target.innerText;
+          this.store.filesTag = navItemCandidate;
           break;
         case 'DISCOVER':
           type = this.$route.params.type;
           fileId = this.$route.params.fileId;
           isCheckPage = this.$route.name.includes('Check');
 
-          switch (event.target.innerText) {
+          switch (navItemCandidate) {
             case 'MAP':
               if(isCheckPage) this.$router.push({name: 'CheckMap', params: { type: type, fileId: fileId }});
               else this.$router.push({name: 'Map', params: { type: type, fileId: fileId }});
@@ -166,40 +185,52 @@ export default {
           break
       }
     },
+    /**
+     * Based on the route.name, decide the navViewName.
+     * @returns {string} the string of navigation name to return
+     */
     getNavViewName() {
-      let name = this.$route.name;
 
-      if(this.$route.name === 'NotFound404') return;
+      let name = this.$route.name;
+      let valueToSet;
+
+      if(this.$route.name === 'NotFound404') {
+        return;
+      }
       this.navViewName = this.$route.matched[1].name.toUpperCase();
       this.store.filesTag = 'ALL';
       switch (this.navViewName) {
         case 'FILES':
-          this.isActive = this.store.filesTag;
+          valueToSet = this.navItemCandidate;
           break;
         case 'DISCOVER':
           switch (name) {
             case 'Map':
             case 'CheckMap':
-              this.isActive = 'MAP';
+              valueToSet = 'MAP';
               break;
             case 'Conformance':
             case 'CheckConformance':
-              this.isActive = 'CONFORMANCE';
+              valueToSet = 'CONFORMANCE';
               break;
             case 'Performanc':
             case 'CheckPerformanc':
-              this.isActive = 'PERFORMANCE';
+              valueToSet = 'PERFORMANCE';
               break;
           }
           break;
         case 'COMPARE':
           switch(name) {
             case 'CompareDashboard':
-              this.isActive = 'DASHBOARD'
+              valueToSet = 'DASHBOARD';
               break;
           }
           break;
       }
+
+      this.setPendingActivePage(valueToSet);
+
+      return valueToSet;
     },
     /**
      * Save button' modal
@@ -217,18 +248,24 @@ export default {
           // 沒有 filter Id, 有暫存 tempFilterId Id 可以另存新檔
           if(this.createFilterId) {
             await this.allMapDataStore.updataFilter();
-            if(this.isUpdataFilter) await savedSuccessfully(this.filterName);
+            if(this.isUpdataFilter) {
+              await savedSuccessfully(this.filterName);
+            }              
           }else if(this.logId){
             isSaved = await saveFilter(this.allMapDataStore.addFilterId);
             // 存檔後為 filterID，換網址不跳頁，使用 push 記錄歷史路由
-            if(isSaved) await this.$router.push(`/discover/filter/${this.createFilterId}/map`);
+            if(isSaved) {
+              await this.$router.push(`/discover/filter/${this.createFilterId}/map`);
+            }
           };
           break;
         case 'CheckMap':
           // 無論 parentLog, parentFilter，做新 filter 皆另存新檔
           isSaved = await saveFilter(this.allMapDataStore.addFilterId);
           // 存檔後為 filterID，換網址不跳頁，使用 push 記錄歷史路由
-          if(isSaved) await this.$router.push(`/discover/filter/${this.createFilterId}/map`);
+          if(isSaved) {
+            await this.$router.push(`/discover/filter/${this.createFilterId}/map`);
+          }
           break;
         case 'Conformance':
         case 'CheckConformance':
@@ -236,18 +273,25 @@ export default {
           // 沒有 check Id, 有暫存 temp Id 可以另存新檔
           if(this.conformanceFilterCreateCheckId || this.conformanceLogCreateCheckId){
             await this.conformanceStore.updataConformance();
-            if(this.isUpdataConformance) await savedSuccessfully(this.conformanceFileName);
+            if(this.isUpdataConformance) {
+              await savedSuccessfully(this.conformanceFileName);
+            }
           } else {
             isSaved = await saveConformance(this.conformanceStore.addConformanceCreateCheckId);
             // 存檔後為 checkID，換網址不跳頁，使用 push 記錄歷史路由
             if(isSaved) {
-              if(this.conformanceLogId) await this.$router.push(`/discover/conformance/log/${this.conformanceLogCreateCheckId}/conformance`);
-              else if(this.conformanceFilterId) await this.$router.push(`/discover/conformance/filter/${this.conformanceFilterCreateCheckId}/conformance`);
+              if(this.conformanceLogId) {
+                await this.$router.push(`/discover/conformance/log/${this.conformanceLogCreateCheckId}/conformance`);
+              }
+              else if(this.conformanceFilterId) {
+                await this.$router.push(`/discover/conformance/filter/${this.conformanceFilterCreateCheckId}/conformance`);
+              }
             }
           }
           break;
       }
-    }
+    },
+    ...mapActions(PageAdminStore, ['setPendingActivePage', ],),
   },
 }
 </script>
diff --git a/src/module/alertModal.js b/src/module/alertModal.js
index c0f51f6..9fabbd7 100644
--- a/src/module/alertModal.js
+++ b/src/module/alertModal.js
@@ -2,6 +2,7 @@ import Swal from 'sweetalert2';
 import AllMapDataStore from '@/stores/allMapData.js';
 import ConformanceStore from '@/stores/conformance.js';
 import FilesStore from '@/stores/files.js';
+import PageAdminStore from '@/stores/pageAdmin.js';
 
 const customClass = {
   container: '!z-[99999]',
@@ -78,6 +79,8 @@ export async function savedSuccessfully(value) {
  */
 export async function leaveFilter(next, addFilterId, toPath, logOut) {
   const allMapDataStore = AllMapDataStore();
+  const pageAdminStore = PageAdminStore();
+
   const result = await Swal.fire({
     title: 'SAVE YOUR FILTER?',
     html: 'If you want to continue using this filter in any other page, please select [Yes].',
@@ -89,22 +92,38 @@ export async function leaveFilter(next, addFilterId, toPath, logOut) {
     showCancelButton: true,
     cancelButtonText: 'No',
     cancelButtonColor: '#94a3b8',
-    customClass: customClass
-  })
+    customClass: customClass,
+  });
+
   if(result.isConfirmed) {
     if(allMapDataStore.createFilterId) {
       await allMapDataStore.updataFilter();
-      if(allMapDataStore.isUpdataFilter) await savedSuccessfully(allMapDataStore.filterName);
+      if(allMapDataStore.isUpdataFilter) {
+        await savedSuccessfully(allMapDataStore.filterName);
+      }
     } else {
       await saveFilter(addFilterId);
     }
+
+    // Handle page admin issue
+    pageAdminStore.copyPendingPageToActivePage();
+
     logOut ? logOut() : next(toPath);
   } else if(result.dismiss === 'cancel') {
+    // Handle page admin issue
+    pageAdminStore.keepPreviousPage();
+
     allMapDataStore.tempFilterId = null;
     logOut ? logOut() : next(toPath);
   } else if(result.dismiss === 'backdrop') {
+    // Handle page admin issue
+    pageAdminStore.keepPreviousPage();
+
     logOut ? null : next(false);
   }
+
+  // In any cases, execute the following
+  pageAdminStore.clearPendingActivePage();
 };
 /**
  * Conformance Saved
diff --git a/src/stores/pageAdmin.js b/src/stores/pageAdmin.js
new file mode 100644
index 0000000..124489a
--- /dev/null
+++ b/src/stores/pageAdmin.js
@@ -0,0 +1,73 @@
+import { defineStore } from "pinia";
+
+export default defineStore('pageAdminStore', {
+  state: () => ({
+     activePage: 'FILES',
+     activeSubPage: 'ALL',
+     previousPage: 'FILES',
+     previousSubPage: 'ALL',
+     pendingActivePage: '',
+     pendingActiveSubPage: '',
+     isPending: false,
+  }),
+  getters: {
+  },
+  actions: {
+    /**
+     * Set Active Page; the page which the user is currently visiting
+     * @param {string} activePage 
+     * @param {string} activeSubPage 
+     */
+    setActivePage(activePage, activeSubpage) {
+      console.log("setActivePage:", activePage, activeSubPage);
+      this.activePage = activePage;
+      this.activeSubPage = activeSubPage;
+    },
+    /**
+    * Set the previous(usually current) page because the user might change her mind when navigating.
+    * @param {string} previoiusPage 
+    * @param {string} previoiusSubPage 
+    */
+    setPrevioiusPage(previoiusPage, previousSubPage) {
+      this.previoiusPage = previoiusPage;
+      this.previoiusSubPage = previousSubPage;
+    },
+    /**
+     * Copy the value of pendingActivePage to activePage
+     */
+    copyPendingPageToActivePage() {
+      console.log("Copy the value of pendingActivePage to activePage\nCopying:", this.pendingActivePage, this.pendingActiveSubPage)
+      this.activePage = this.pendingActivePage;
+      this.activeSubPage = this.pendingActiveSubPage;
+    },    
+    /**
+     * Set Pending active Page, meaning we are not sure if user will chang her mind later on.
+     * Also, start pending state.
+     * Often, user triggers the modal and the pending state starts.
+     * @param {string} pendingActivePage 
+     */
+    setPendingActivePage(argPendingActivePage, argPendingActiveSubPage) {
+      this.pendingActivePage = argPendingActivePage;
+      this.pendingActiveSubPage = argPendingActiveSubPage;
+      this.isPending = true;
+    },
+    /**
+     * Set Pending active Page to empty string; we call this right after we just decide an activePage.
+     * Also, stop pending state.
+     */
+    clearPendingActivePage(){
+      this.pendingActivePage = '';
+      this.pendingActiveSubPage = '';
+      this.isPending = false;
+    },
+    /**
+     * When user dismiss the popup modal, we don't apply the new page,
+     * instead, we apply the previous page.
+     */
+    keepPreviousPage() {
+      this.activePage = this.previousPage;
+      this.activeSubPage = this.previousSubPage;
+      this.isPending = false;
+    }
+  },
+})
\ No newline at end of file
diff --git a/src/views/Login/index.vue b/src/views/Login/index.vue
index 02d46f6..a255c4f 100644
--- a/src/views/Login/index.vue
+++ b/src/views/Login/index.vue
@@ -89,7 +89,9 @@ export default {
      */
     changeHandler(event) {
       let inputValue = event.target.value;
-      if(inputValue !== '') this.isInvalid = false;
+      if(inputValue !== '') {
+        this.isInvalid = false;
+      }
     },
   },
 };
diff --git a/src/views/MainContainer.vue b/src/views/MainContainer.vue
index e0eea52..8a03f6c 100644
--- a/src/views/MainContainer.vue
+++ b/src/views/MainContainer.vue
@@ -10,7 +10,7 @@
 </template>
 
 <script>
-import { storeToRefs } from 'pinia';
+import { storeToRefs, mapActions, } from 'pinia';
 import LoadingStore from '@/stores/loading.js';
 import AllMapDataStore from '@/stores/allMapData.js';
 import ConformanceStore from '@/stores/conformance.js';
@@ -18,6 +18,7 @@ import Header from "@/components/Header.vue";
 import Navbar from "@/components/Navbar.vue";
 import Loading from '@/components/Loading.vue';
 import { leaveFilter, leaveConformance } from '@/module/alertModal.js';
+import PageAdminStore from '@/stores/pageAdmin.js';
 
 export default {
   name: 'MainContainer',
@@ -28,13 +29,21 @@ export default {
     const { tempFilterId, createFilterId,  temporaryData, postRuleData, ruleData } = storeToRefs(allMapDataStore);
     const {  conformanceLogTempCheckId, conformanceFilterTempCheckId } = storeToRefs(conformanceStore);
 
-    return { loadingStore, temporaryData, tempFilterId, createFilterId, postRuleData, ruleData, conformanceLogTempCheckId, conformanceFilterTempCheckId, allMapDataStore, conformanceStore };
+    return {
+      loadingStore, temporaryData, tempFilterId,
+      createFilterId, postRuleData, ruleData,
+      conformanceLogTempCheckId, conformanceFilterTempCheckId,
+      allMapDataStore, conformanceStore,
+    };
   },
   components: {
     Header,
     Navbar,
     Loading
   },
+  methods: {
+    ...mapActions(PageAdminStore, ['copyPendingPageToActivePage',],),
+  },
   created() {
     // Save token in Headers.
     const token = document.cookie.replace(/(?:(?:^|.*;\s*)luciaToken\s*\=\s*([^;]*).*$)|^.*$/, "$1");
@@ -46,9 +55,17 @@ export default {
       // 傳給 Map，通知 Sidebar 要關閉。
       this.$emitter.emit('leaveFilter', false);
       leaveFilter(next, this.allMapDataStore.addFilterId, to.path)
-    } else if((this.$route.name === 'Conformance' || this.$route.name === 'CheckConformance') && (this.conformanceLogTempCheckId || this.conformanceFilterTempCheckId)) {
+    } else if((this.$route.name === 'Conformance' || this.$route.name === 'CheckConformance') 
+        && (this.conformanceLogTempCheckId || this.conformanceFilterTempCheckId)) {
       leaveConformance(next, this.conformanceStore.addConformanceCreateCheckId, to.path)
-    } else next();
+    } else {
+      // In this else block:
+      // for those pages who don't need popup modals, we handle page administration right now.
+      // By calling the following code, we decide the next visiting page.
+      this.copyPendingPageToActivePage();
+
+      next();
+    };
   },
 };
 </script>