diff --git a/src/editor.html b/src/editor.html
index 39525af..be7cd73 100644
--- a/src/editor.html
+++ b/src/editor.html
@@ -80,6 +80,48 @@
   </div>
 </div>
 
+<div class="modal fade" id="open-file" tabindex="-1">
+  <div class="modal-dialog">
+    <div class="modal-content">
+      <div class="modal-body">
+        <h5>Are you sure that you want to open a file? You will lose unsaved data.</h5>
+      </div>
+      <div class="modal-footer">
+        <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">No, stay here</button>
+        <button id="confirm-open-file" type="button" class="btn btn-danger" data-bs-dismiss="modal">Yes, open file</button>
+      </div>
+    </div>
+  </div>
+</div>
+
+<div class="modal fade" id="start-new" tabindex="-1">
+  <div class="modal-dialog">
+    <div class="modal-content">
+      <div class="modal-body">
+        <h5>Are you sure that you want to start a new file? You will lose unsaved data.</h5>
+      </div>
+      <div class="modal-footer">
+        <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">No, stay here</button>
+        <button id="confirm-start-new" type="button" class="btn btn-danger" data-bs-dismiss="modal">Yes, start new</button>
+      </div>
+    </div>
+  </div>
+</div>
+
+<div class="modal fade" id="quit" tabindex="-1">
+  <div class="modal-dialog">
+    <div class="modal-content">
+      <div class="modal-body">
+        <h5>Are you sure that you want to quit? You will lose unsaved data.</h5>
+      </div>
+      <div class="modal-footer">
+        <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">No, stay open</button>
+        <button id="confirm-quit" type="button" class="btn btn-danger" data-bs-dismiss="modal">Yes, quit</button>
+      </div>
+    </div>
+  </div>
+</div>
+
 <script>
   if (typeof module === 'object') {
     window.module = module;
diff --git a/src/index.ts b/src/index.ts
index 118eef6..ad989cd 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -31,7 +31,6 @@ let schema_updaters = {
 log.transports.file.resolvePath = () => path.join(app.getAppPath(), "debug.log");
 
 const store = new Store();
-let current_file = null;
 let debug = false;
 let menu_template:MenuItemConstructorOptions[] = [
   {
@@ -51,11 +50,18 @@ let menu_template:MenuItemConstructorOptions[] = [
           window.webContents.send("save", true);
         }
       },
+      {
+        label: "New File",
+        accelerator: "Ctrl+N",
+        click: function (item, window, event) {
+          window.webContents.send("try-start-new");
+        }
+      },
       {
         label: "Open",
         accelerator: "Ctrl+O",
-        click: function () {
-          openFile();
+        click: function (item, window, event) {
+          window.webContents.send("try-open");
         }
       },
       {
@@ -64,8 +70,8 @@ let menu_template:MenuItemConstructorOptions[] = [
       },
       {
         label: "Exit",
-        click: function () {
-          app.quit();
+        click: function (item, window, event) {
+          window.webContents.send("try-quit");
         }
       }
     ]
@@ -125,7 +131,7 @@ app.on('ready', start);
 // explicitly with Cmd + Q.
 app.on('window-all-closed', () => {
   if (process.platform !== 'darwin') {
-    app.quit();
+    app.exit();
   }
 });
 
@@ -137,6 +143,11 @@ app.on('activate', () => {
   }
 });
 
+app.on("before-quit", (event) => {
+  event.preventDefault();
+  BrowserWindow.getFocusedWindow().webContents.send("try-quit");
+})
+
 function start() {
   if (process.argv.includes("--debug")) {
     debug = true;
@@ -170,7 +181,7 @@ function createSplashScreen() {
   // store.openInEditor();
 }
 
-function createEditorWindow(json) {
+function createEditorWindow(file_name, json) {
   let main_window = new BrowserWindow({
     width: 1000,
     height: 600,
@@ -179,12 +190,16 @@ function createEditorWindow(json) {
       nodeIntegration: true
     }
   })
+      .on("close", (event) => {
+        event.preventDefault();
+        main_window.webContents.send("try-close-window");
+      })
   main_window.maximize();
   updateMenuBar();
 
   main_window.loadFile(path.join(app.getAppPath(), "src/editor.html"))
     .then(() => {
-      main_window.webContents.send("open", json);
+      main_window.webContents.send("open", file_name, json);
     });
   // Open the DevTools.
   if (debug) {
@@ -196,8 +211,8 @@ function createEditorWindow(json) {
 function createNew() {
   let old_window = BrowserWindow.getFocusedWindow();
   let json = loadJson(path.join(app.getAppPath(), "src/default.json"));
-  let main_window = createEditorWindow(json);
-  old_window.close();
+  let main_window = createEditorWindow(null, json);
+  old_window.destroy();
 }
 
 function chooseFile(title, for_save=false) {
@@ -234,29 +249,29 @@ function openFile(file_path="", new_file=false) {
     if (result) {
       let json = getUpdatedJson(result);
       updateRecentFiles(file_path);
-      current_file = file_path
       if (new_file) {
         let old_window = BrowserWindow.getFocusedWindow();
-        createEditorWindow(json);
+        createEditorWindow(file_path, json);
         old_window.close();
       } else {
         let window = BrowserWindow.getFocusedWindow();
-        window.webContents.send("open", json);
+        window.webContents.send("open", file_path, json);
       }
     }
   }
 }
 
-function saveFile(json_data, create_new_file) {
-  if (current_file == null || create_new_file) {
+function saveFile(file_name, json_data) {
+  if (file_name == null) {
     let file_path = chooseFile("Save website data", true);
     if (file_path) {
       updateRecentFiles(file_path);
-      current_file = file_path;
+      file_name = file_path;
     }
   }
-  if (current_file) {
-    fs.writeFileSync(current_file, JSON.stringify(json_data, null, 4));
+  if (file_name) {
+    fs.writeFileSync(file_name, JSON.stringify(json_data, null, 4));
+    BrowserWindow.getFocusedWindow().webContents.send("file-saved", file_name);
   }
 }
 
@@ -292,7 +307,7 @@ function updateMenuBar() {
         if (fs.existsSync(file)) {
           menu.submenu.push({
             label: file, click: () => {
-              openFile(file);
+              BrowserWindow.getFocusedWindow().webContents.send("try-open", file);
             }
           });
         }
@@ -397,10 +412,18 @@ ipcMain.on("create-new", (event) => {
   createNew();
 })
 
-ipcMain.on("save", (event, json_data, create_new_file) => {
-  saveFile(json_data, create_new_file);
+ipcMain.on("save", (event, file_name, json_data) => {
+  saveFile(file_name, json_data);
 })
 
-ipcMain.on("open", (event, file_path="") => {
-  openFile(file_path, true)
+ipcMain.on("open", (event, file_path="", new_file=false) => {
+  openFile(file_path, new_file)
+})
+
+ipcMain.on("quit", (event) => {
+  app.exit();
+})
+
+ipcMain.on("close-window", (event) => {
+  BrowserWindow.getFocusedWindow().destroy();
 })
diff --git a/src/js/editor.ts b/src/js/editor.ts
index 3be8be8..36ab32f 100644
--- a/src/js/editor.ts
+++ b/src/js/editor.ts
@@ -1,13 +1,15 @@
 import {ipcRenderer, clipboard} from 'electron';
 import * as $ from "../../third_party/js/jquery-3.5.1.js";
-import * as Sortable from "../../third_party/js/Sortable.js"
-import * as Selectable from "../../third_party/js/selectable.js"
+import * as Sortable from "../../third_party/js/Sortable.js";
+import * as Selectable from "../../third_party/js/selectable.js";
 import * as util from "util";
 let json_data;
 let tables_data;
 let current_table;
 let is_positioning = false;
 let undo_history = {};
+let current_file_name = null;
+let current_file_modified = false;
 let nav = $("nav");
 let tables = $("#tables");
 let nav_scroll = nav.scrollLeft();
@@ -21,7 +23,9 @@ let detail_column_sortable = $("#detail-column-sortable");
 let detail_cell_text = $("#detail-cell-text");
 let position_edit_btn = $("#position-edit");
 
-function openFile(json) {
+function openFile(file_name, json) {
+	updateSaveStatus(false, file_name);
+	resetUndoHistory();
 	json_data = json;
 	tables_data = json["tables"];
 	current_table = null;
@@ -29,7 +33,11 @@ function openFile(json) {
 }
 
 function saveFile(create_new_file) {
-	ipcRenderer.send("save", json_data, create_new_file);
+	if (create_new_file) {
+		ipcRenderer.send("save", null, json_data);
+	} else {
+		ipcRenderer.send("save", current_file_name, json_data);
+	}
 }
 
 function clearPage() {
@@ -307,6 +315,7 @@ function addTable() {
 	tables_data.push(table_data);
 	getSelectionData(true);
 	generateTable(table_data);
+	updateSaveStatus(true);
 }
 
 function duplicateTable(table_id) {
@@ -327,6 +336,7 @@ function duplicateTable(table_id) {
 		}
 	}
 	refreshPage();
+	updateSaveStatus(true);
 }
 
 function insertColumn(table_id, index=-1) {
@@ -459,6 +469,7 @@ function deleteColumn(table_id, col_index) {
 		}
 	}
 	refreshPage();
+	addUndoHistory(current_table);
 }
 
 function deleteRow(table_id, row_index) {
@@ -469,6 +480,7 @@ function deleteRow(table_id, row_index) {
 		}
 	}
 	refreshPage();
+	addUndoHistory(current_table);
 }
 
 function cellContextMenu(event, cell_id) {
@@ -623,6 +635,9 @@ function navContextMenu(event, table_id) {
 				})
 				menu.remove();
 			}));
+		$("#delete-table")[0].addEventListener("hidden.bs.modal", (event) => {
+			$("#confirm-delete-table").off();
+		})
 	}
 	let max_height = $(document).height();
 	let max_width = $(document).width();
@@ -640,9 +655,7 @@ function cellInlineEdit(cell_id) {
 	let target: JQuery = $("#"+cell_id);
 	let width = target.outerWidth();
 	let height = target.outerHeight();
-	console.log(height);
 	let text_area = $("<textarea>")
-		// .css({"width": width, "height": height})
 		.on("focusout", () => {
 			closeCellInlineEdit(true);
 		})
@@ -735,6 +748,7 @@ function moveTable(old_index, new_index) {
 		tables_data.splice(new_index, 0, table_data);
 		getSelectionData(true);
 		addUndoHistory(current_table);
+		updateSaveStatus(true);
 	}
 }
 
@@ -750,6 +764,7 @@ function moveRow(table_id, old_index, new_index) {
 		}
 		getSelectionData(true);
 		addUndoHistory(current_table);
+		updateSaveStatus(true);
 	}
 }
 
@@ -765,6 +780,7 @@ function moveCol(table_id, old_index, new_index) {
 		getSelectionData(true)
 		addUndoHistory(current_table);
 		refreshPage();
+		updateSaveStatus(true);
 	}
 }
 
@@ -1070,6 +1086,7 @@ function addUndoHistory(table_id) {
 			if (!util.isDeepStrictEqual(tables_data[i], undo_history[table_id]["history"][index])) {
 				undo_history[table_id]["history"].splice(0, index, makeCopy(tables_data[i]));
 				undo_history[table_id]["index"] = 0;
+				updateSaveStatus(true);
 			}
 		}
 	}
@@ -1086,6 +1103,7 @@ function undo() {
 			}
 		}
 		refreshPage();
+		updateSaveStatus(true);
 	}
 }
 
@@ -1100,11 +1118,33 @@ function redo() {
 			}
 		}
 		refreshPage();
+		updateSaveStatus(true);
 	}
 }
 
 function deleteUndoHistory(table_id) {
 	delete undo_history[table_id];
+	updateSaveStatus(true);
+}
+
+function resetUndoHistory() {
+	undo_history = {};
+}
+
+function updateSaveStatus(file_modified, new_file_name=null) {
+	current_file_modified = file_modified;
+	let file_name = current_file_name;
+	if (new_file_name != null) {
+		current_file_name = new_file_name;
+		file_name = new_file_name;
+	} else if (file_name == null) {
+		file_name = "[untitled]"
+	}
+	if (current_file_modified) {
+		$(document).attr("title", "Web Editor - "+file_name+"*");
+	} else {
+		$(document).attr("title", "Web Editor - "+file_name);
+	}
 }
 
 function getColumnIDs(columns): Array<string> {
@@ -1276,8 +1316,8 @@ $(document).on("keydown", (event: JQuery.KeyDownEvent) => {
 	}
 })
 
-ipcRenderer.on("open", (event, json) => {
-	openFile(json);
+ipcRenderer.on("open", (event, file_name, json) => {
+	openFile(file_name, json);
 })
 
 ipcRenderer.on("save", (event, create_new_file) => {
@@ -1302,3 +1342,71 @@ ipcRenderer.on("undo", (event) => {
 ipcRenderer.on("redo", (event) => {
 	redo();
 })
+
+ipcRenderer.on("file-saved", (event, file_name) => {
+	updateSaveStatus(false, file_name);
+})
+
+ipcRenderer.on("try-open", (event, file_name) => {
+	if (current_file_modified) {
+		$("#confirm-open-file").one("click", () => {
+			ipcRenderer.send("open", file_name);
+		})
+		let modal_el = $("#open-file")
+		let modal = new bootstrap.Modal(modal_el[0]);
+		modal.show();
+		modal_el[0].addEventListener("hidden.bs.modal", (event) => {
+			$("#confirm-open-file").off();
+		})
+	} else {
+		ipcRenderer.send("open", file_name);
+	}
+})
+
+ipcRenderer.on("try-start-new", (event, file_name) => {
+	if (current_file_modified) {
+		$("#confirm-start-new").one("click", () => {
+			ipcRenderer.send("create-new", file_name);
+		})
+		let modal_el = $("#start-new")
+		let modal = new bootstrap.Modal(modal_el[0]);
+		modal.show();
+		modal_el[0].addEventListener("hidden.bs.modal", (event) => {
+			$("#confirm-start-new").off();
+		})
+	} else {
+		ipcRenderer.send("create-new", file_name);
+	}
+})
+
+ipcRenderer.on("try-quit", (event) => {
+	if (current_file_modified) {
+		$("#confirm-quit").one("click", () => {
+			ipcRenderer.send("quit");
+		})
+		let modal_el = $("#quit")
+		let modal = new bootstrap.Modal(modal_el[0]);
+		modal.show();
+		modal_el[0].addEventListener("hidden.bs.modal", (event) => {
+			$("#confirm-quit").off();
+		})
+	} else {
+		ipcRenderer.send("quit");
+	}
+})
+
+ipcRenderer.on("try-close-window", (event) => {
+	if (current_file_modified) {
+		$("#confirm-quit").one("click", () => {
+			ipcRenderer.send("close-window");
+		})
+		let modal_el = $("#quit")
+		let modal = new bootstrap.Modal(modal_el[0]);
+		modal.show();
+		modal_el[0].addEventListener("hidden.bs.modal", (event) => {
+			$("#confirm-quit").off();
+		})
+	} else {
+		ipcRenderer.send("close-window");
+	}
+})
diff --git a/src/js/splash.ts b/src/js/splash.ts
index 6239c96..90b9faa 100644
--- a/src/js/splash.ts
+++ b/src/js/splash.ts
@@ -15,7 +15,7 @@ async function showRecentFiles() {
 				.text(file.replace(/^.*[\\\/]/, ''))
 				.attr({"data-bs-toggle": "tooltip", "data-bs-placement": "bottom", "title": file})
 				.on("click", () => {
-					ipcRenderer.send("open", file);
+					ipcRenderer.send("open", file, true);
 				})
 				.append($("<a>")
 					.addClass("btn-close")
@@ -40,5 +40,5 @@ $("#create-new").on("click", () => {
 });
 
 $("#open-file").on("click", () => {
-	ipcRenderer.send("open");
+	ipcRenderer.send("open", "", true);
 })