diff --git a/api/js/etemplate/et2_core_inputWidget.js b/api/js/etemplate/et2_core_inputWidget.js
index 3aad70a0da..4fed8a4251 100644
--- a/api/js/etemplate/et2_core_inputWidget.js
+++ b/api/js/etemplate/et2_core_inputWidget.js
@@ -58,6 +58,14 @@ var et2_inputWidget = /** @class */ (function (_super) {
         _super.prototype.destroy.call(this);
         this._labelContainer = null;
     };
+    /**
+     * Make sure dirty flag is properly set
+     */
+    et2_inputWidget.prototype.doLoadingFinished = function () {
+        var result = _super.prototype.doLoadingFinished.call(this);
+        this.resetDirty();
+        return result;
+    };
     /**
      * Load the validation errors from the server
      *
@@ -212,7 +220,25 @@ var et2_inputWidget = /** @class */ (function (_super) {
         return this._oldValue;
     };
     et2_inputWidget.prototype.isDirty = function () {
-        return this._oldValue != this.getValue();
+        var value = this.getValue();
+        if (typeof value !== typeof this._oldValue) {
+            return true;
+        }
+        if (this._oldValue === value) {
+            return false;
+        }
+        switch (typeof this._oldValue) {
+            case "object":
+                if (this._oldValue.length !== value.length)
+                    return true;
+                for (var key in this._oldValue) {
+                    if (this._oldValue[key] !== value[key])
+                        return true;
+                }
+                return false;
+            default:
+                return this._oldValue != value;
+        }
     };
     et2_inputWidget.prototype.resetDirty = function () {
         this._oldValue = this.getValue();
diff --git a/api/js/etemplate/et2_core_inputWidget.ts b/api/js/etemplate/et2_core_inputWidget.ts
index 8a241e24c8..0230a1dd83 100644
--- a/api/js/etemplate/et2_core_inputWidget.ts
+++ b/api/js/etemplate/et2_core_inputWidget.ts
@@ -96,6 +96,18 @@ export class et2_inputWidget extends et2_valueWidget implements et2_IInput, et2_
 		this._labelContainer = null;
 	}
 
+	/**
+	 * Make sure dirty flag is properly set
+	 */
+	doLoadingFinished() : boolean | JQueryPromise<unknown>
+	{
+		let result = super.doLoadingFinished();
+
+		this.resetDirty();
+
+		return result;
+	}
+
 	/**
 	 * Load the validation errors from the server
 	 *
@@ -300,7 +312,27 @@ export class et2_inputWidget extends et2_valueWidget implements et2_IInput, et2_
 
 	isDirty()
 	{
-		return this._oldValue != this.getValue();
+		let value = this.getValue();
+		if(typeof value !== typeof this._oldValue)
+		{
+			return true;
+		}
+		if(this._oldValue === value)
+		{
+			return false;
+		}
+		switch(typeof this._oldValue)
+		{
+			case "object":
+				if(this._oldValue.length !== value.length) return true;
+				for(let key in this._oldValue)
+				{
+					if(this._oldValue[key] !== value[key]) return true;
+				}
+				return false;
+			default:
+				return this._oldValue != value;
+		}
 	}
 
 	resetDirty()
diff --git a/api/js/etemplate/et2_extension_customfields.js b/api/js/etemplate/et2_extension_customfields.js
index cf1c8746d0..f65c60addc 100644
--- a/api/js/etemplate/et2_extension_customfields.js
+++ b/api/js/etemplate/et2_extension_customfields.js
@@ -316,10 +316,10 @@ var et2_customfields_list = /** @class */ (function (_super) {
         return value;
     };
     et2_customfields_list.prototype.isDirty = function () {
-        var dirty = true;
+        var dirty = false;
         for (var field_name in this.widgets) {
             if (this.widgets[field_name].isDirty) {
-                dirty = dirty && this.widgets[field_name].isDirty();
+                dirty = dirty || this.widgets[field_name].isDirty();
             }
         }
         return dirty;
diff --git a/api/js/etemplate/et2_extension_customfields.ts b/api/js/etemplate/et2_extension_customfields.ts
index 6c1b9c3606..a5a1bd4d93 100644
--- a/api/js/etemplate/et2_extension_customfields.ts
+++ b/api/js/etemplate/et2_extension_customfields.ts
@@ -430,12 +430,12 @@ export class et2_customfields_list extends et2_valueWidget implements et2_IDetac
 
 	isDirty( )
 	{
-		let dirty = true;
+		let dirty = false;
 		for(let field_name in this.widgets)
 		{
 			if(this.widgets[field_name].isDirty)
 			{
-				dirty = dirty && this.widgets[field_name].isDirty();
+				dirty = dirty || this.widgets[field_name].isDirty();
 			}
 		}
 		return dirty;
diff --git a/api/js/etemplate/et2_widget_selectbox.js b/api/js/etemplate/et2_widget_selectbox.js
index 723c28d0ec..e0ec8e6202 100644
--- a/api/js/etemplate/et2_widget_selectbox.js
+++ b/api/js/etemplate/et2_widget_selectbox.js
@@ -344,8 +344,8 @@ var et2_selectbox = /** @class */ (function (_super) {
         this.setDOMNode(node[0]);
     };
     et2_selectbox.prototype.doLoadingFinished = function () {
-        _super.prototype.doLoadingFinished.call(this);
         this.set_tags(this.options.tags, this.options.width);
+        _super.prototype.doLoadingFinished.call(this);
         return true;
     };
     et2_selectbox.prototype.loadFromXML = function (_node) {
@@ -1366,6 +1366,12 @@ var et2_selectbox_ro = /** @class */ (function (_super) {
     et2_selectbox_ro.prototype.getValue = function () {
         return null;
     };
+    /**
+     * Readonly selectbox can't be dirty
+     */
+    et2_selectbox_ro.prototype.isDirty = function () {
+        return false;
+    };
     /**
      * Functions for et2_IDetachedDOM
      */
diff --git a/api/js/etemplate/et2_widget_selectbox.ts b/api/js/etemplate/et2_widget_selectbox.ts
index 59d6cc844d..017b4995e7 100644
--- a/api/js/etemplate/et2_widget_selectbox.ts
+++ b/api/js/etemplate/et2_widget_selectbox.ts
@@ -484,10 +484,10 @@ export class et2_selectbox extends et2_inputWidget
 
 	doLoadingFinished()
 	{
-		super.doLoadingFinished();
-
 		this.set_tags(this.options.tags, this.options.width);
 
+		super.doLoadingFinished();
+
 		return true;
 	}
 
@@ -1679,6 +1679,14 @@ export class et2_selectbox_ro extends et2_selectbox implements et2_IDetachedDOM
 		return null;
 	}
 
+	/**
+	 * Readonly selectbox can't be dirty
+	 */
+	isDirty()
+	{
+		return false;
+	}
+
 	/**
 	 * Functions for et2_IDetachedDOM
 	 */
diff --git a/api/js/etemplate/et2_widget_tabs.js b/api/js/etemplate/et2_widget_tabs.js
index 2044ca94c4..ff579dc56d 100644
--- a/api/js/etemplate/et2_widget_tabs.js
+++ b/api/js/etemplate/et2_widget_tabs.js
@@ -218,6 +218,7 @@ var et2_tabbox = /** @class */ (function (_super) {
             }
             jQuery.when.apply(jQuery, promises).then(function () {
                 tab_deferred.resolve();
+                tabs.resetDirty();
             });
         }, 0);
         return tab_deferred.promise();
diff --git a/api/js/etemplate/et2_widget_tabs.ts b/api/js/etemplate/et2_widget_tabs.ts
index 329fb95769..3802fb9995 100644
--- a/api/js/etemplate/et2_widget_tabs.ts
+++ b/api/js/etemplate/et2_widget_tabs.ts
@@ -274,6 +274,7 @@ class et2_tabbox extends et2_valueWidget implements et2_IInput,et2_IResizeable,e
 			}
 			jQuery.when.apply(jQuery,promises).then(function() {
 				tab_deferred.resolve();
+				tabs.resetDirty();
 			});
 		},0);
 
diff --git a/api/js/etemplate/et2_widget_taglist.js b/api/js/etemplate/et2_widget_taglist.js
index ee8f9e7b0e..dc89d07888 100644
--- a/api/js/etemplate/et2_widget_taglist.js
+++ b/api/js/etemplate/et2_widget_taglist.js
@@ -279,6 +279,7 @@ var et2_taglist = /** @class */ (function (_super) {
         this.div.on('blur', 'input', function () {
             jQuery('.ms-ctn-focus', widget.div).removeClass('ms-ctn-focus');
         });
+        this.resetDirty();
         return true;
     };
     /**
diff --git a/api/js/etemplate/et2_widget_taglist.ts b/api/js/etemplate/et2_widget_taglist.ts
index d264137039..4eb9b624e9 100644
--- a/api/js/etemplate/et2_widget_taglist.ts
+++ b/api/js/etemplate/et2_widget_taglist.ts
@@ -430,6 +430,8 @@ export class et2_taglist extends et2_selectbox implements et2_IResizeable
 		this.div.on('blur', 'input', function() {
 			jQuery('.ms-ctn-focus', widget.div).removeClass('ms-ctn-focus');
 		});
+
+		this.resetDirty();
 		return true;
 	}
 
diff --git a/api/js/etemplate/etemplate2.js b/api/js/etemplate/etemplate2.js
index ed20f628eb..f1960b3947 100644
--- a/api/js/etemplate/etemplate2.js
+++ b/api/js/etemplate/etemplate2.js
@@ -274,20 +274,34 @@ var etemplate2 = /** @class */ (function () {
      * calls, eg. via et2_dialog.
      */
     etemplate2.prototype.bind_unload = function () {
+        // Prompt user to save for dirty popups
+        if (window !== egw_topWindow() && !this.close_prompt) {
+            this.close_prompt = this._close_changed_prompt.bind(this);
+            window.addEventListener("beforeunload", this.close_prompt);
+        }
         if (this._etemplate_exec_id) {
             this.destroy_session = jQuery.proxy(function (ev) {
                 // need to use async === "keepalive" to run via beforeunload
                 egw.json("EGroupware\\Api\\Etemplate::ajax_destroy_session", [this._etemplate_exec_id], null, null, "keepalive").sendRequest();
             }, this);
-            if (!window.onbeforeunload) {
-                window.onbeforeunload = this.destroy_session;
-            }
+            window.addEventListener("beforeunload", this.destroy_session);
         }
     };
+    etemplate2.prototype._close_changed_prompt = function (e) {
+        if (!this.isDirty()) {
+            return;
+        }
+        // Cancel the event
+        e.preventDefault(); // If you prevent default behavior in Mozilla Firefox prompt will always be shown
+        // Chrome requires returnValue to be set
+        e.returnValue = '';
+    };
     /**
      * Unbind our unload handler
      */
     etemplate2.prototype.unbind_unload = function () {
+        window.removeEventListener("beforeunload", this.destroy_session);
+        window.removeEventListener("beforeunload", this.close_prompt);
         if (window.onbeforeunload === this.destroy_session) {
             window.onbeforeunload = null;
         }
diff --git a/api/js/etemplate/etemplate2.ts b/api/js/etemplate/etemplate2.ts
index f53a1db445..8136f40a81 100644
--- a/api/js/etemplate/etemplate2.ts
+++ b/api/js/etemplate/etemplate2.ts
@@ -107,6 +107,7 @@ export class etemplate2
 
 	private resize_timeout: number | boolean;
 	private destroy_session: any;
+	private close_prompt: any;
 	private app_obj: EgwApp;
 	app: string;
 
@@ -344,6 +345,12 @@ export class etemplate2
 	 */
 	bind_unload()
 	{
+		// Prompt user to save for dirty popups
+		if(window !== egw_topWindow() && !this.close_prompt)
+		{
+			this.close_prompt = this._close_changed_prompt.bind(this);
+			window.addEventListener("beforeunload", this.close_prompt);
+		}
 		if (this._etemplate_exec_id)
 		{
 			this.destroy_session = jQuery.proxy(function (ev)
@@ -353,18 +360,31 @@ export class etemplate2
 				         [this._etemplate_exec_id], null, null, "keepalive").sendRequest();
 			}, this);
 
-			if (!window.onbeforeunload)
-			{
-				window.onbeforeunload = this.destroy_session;
-			}
+			window.addEventListener("beforeunload", this.destroy_session);
 		}
 	}
 
+	private _close_changed_prompt(e : BeforeUnloadEvent)
+	{
+		if(!this.isDirty())
+		{
+			return;
+		}
+
+		// Cancel the event
+        e.preventDefault(); // If you prevent default behavior in Mozilla Firefox prompt will always be shown
+
+		// Chrome requires returnValue to be set
+		e.returnValue = '';
+	}
+
 	/**
 	 * Unbind our unload handler
 	 */
 	unbind_unload()
 	{
+		window.removeEventListener("beforeunload", this.destroy_session);
+		window.removeEventListener("beforeunload", this.close_prompt);
 		if (window.onbeforeunload === this.destroy_session)
 		{
 			window.onbeforeunload = null;
diff --git a/calendar/js/app.js b/calendar/js/app.js
index ab77efa985..f869d86c30 100644
--- a/calendar/js/app.js
+++ b/calendar/js/app.js
@@ -386,9 +386,7 @@ var CalendarApp = /** @class */ (function (_super) {
                     //send Syncronus ajax request to the server to unlock the on close entry
                     //set onbeforeunload with json request to send request when the window gets close by X button
                     if (content.data.lock_token) {
-                        window.onbeforeunload = function () {
-                            this.egw.json('calendar.calendar_uiforms.ajax_unlock', [content.data.id, content.data.lock_token], null, true, "keepalive", null).sendRequest();
-                        };
+                        window.addEventListener("beforeunload", this._unlock.bind(this));
                     }
                 }
                 this.alarm_custom_date();
@@ -788,6 +786,15 @@ var CalendarApp = /** @class */ (function (_super) {
             sortable.sortable('disable');
         }
     };
+    /**
+     * Unlock the event before closing the popup
+     *
+     * @private
+     */
+    CalendarApp.prototype._unlock = function () {
+        var content = this.et2.getArrayMgr('content');
+        this.egw.json('calendar.calendar_uiforms.ajax_unlock', [content.data.id, content.data.lock_token], null, this, "keepalive", null).sendRequest();
+    };
     /**
      * Bind scroll event
      * When the user scrolls, we'll move enddate - startdate days
diff --git a/calendar/js/app.ts b/calendar/js/app.ts
index 1ff37da86b..707b31a0e3 100644
--- a/calendar/js/app.ts
+++ b/calendar/js/app.ts
@@ -286,10 +286,7 @@ class CalendarApp extends EgwApp
 					//set onbeforeunload with json request to send request when the window gets close by X button
 					if (content.data.lock_token)
 					{
-						window.onbeforeunload = function () {
-							this.egw.json('calendar.calendar_uiforms.ajax_unlock',
-							[content.data.id, content.data.lock_token],null,true,"keepalive",null).sendRequest();
-						};
+						window.addEventListener("beforeunload", this._unlock.bind(this));
 					}
 				}
 				this.alarm_custom_date();
@@ -758,6 +755,17 @@ class CalendarApp extends EgwApp
 		}
 	}
 
+	/**
+	 * Unlock the event before closing the popup
+	 *
+	 * @private
+	 */
+	private _unlock () {
+		const content = this.et2.getArrayMgr('content');
+		this.egw.json('calendar.calendar_uiforms.ajax_unlock',
+		              [content.data.id, content.data.lock_token],null,this,"keepalive",null).sendRequest();
+	}
+
 	/**
 	 * Bind scroll event
 	 * When the user scrolls, we'll move enddate - startdate days