How to make the 'Are you sure you want to navigate away from this page' warning message in browser?

Question

I have a web page that contains a textbox and a submit button. When the user edits the text in the textbox and clicks another link (not the submit button) how do I display the 'Are you sure you want to navigate away from this page' popup message?

I have researched this on the net and found a few javascript examples. Is this the only way you can do this? If not, what is the best way to do it?

Answer 1

This is one of the multiple ways to achieve the same thing

function goodbye(e) {
    if(!e) e = window.event;
    //e.cancelBubble is supported by IE - this will kill the bubbling process.
    e.cancelBubble = true;
    e.returnValue = 'You sure you want to leave?'; //This is displayed on the dialog

    //e.stopPropagation works in Firefox.
    if (e.stopPropagation) {
        e.stopPropagation();
        e.preventDefault();
    }
}
window.onbeforeunload=goodbye;

got it from here open js

Answer 2

Only the unload() event will work on JS. You can't manage it on the server.