Activating OnBeforeUnload ONLY when field values have changed

Question

What I\'m trying to achieve is to Warn the user of unsaved changes if he/she tries to close a page or navigate away from it without saving first.

I\'ve managed to g

Answer 1

Try your logic in a different manner. Meaning, put the logic for checking the value of the input field in your onbeforeunload method.

window.onbeforeunload = function () { 
    if ($("#is_modified").val() == 'true') { 
        return "You have unsaved changes."; 
    } else { 
        return true; // I think true is the proper value here 
    } 
};