Question

I’m working under ASP.NET and I wonder if is possible to display a custom save prompt (let’s say a div with styles, a message and some buttons) when the user is trying to leave the page.
I’ve seen the onunload and onbeforeunload JS events.
The onunload event seems to does not work for my purpose, because I display the message but I can’t prevent the user from leaving the page.
The onbeforunload could be useful just because I can prevent the user from leaving the page, but the prompt is the responsibility of the navigator, and I want to implement it!

I think there is not another option than onbeforeunload to warn the user about possible losses of work but I expect helpful answers.

Related question: Prompting user to save when they leave a page

Answer 1

There is not another solution than using onbeforeunload JavaScript event. The prompt is implemented by each navigator independently, and just a piece of text can be displayed.

window.onbeforeunload = function(){ 
    return 'I want to show this text. Do u want to leave?'; 
};