how can i prevent onbeforeunload from firing when a certain condition is met?

Question

i have a page on which i want to confirm if the user wants to leave. i have to confirm only when a certain condition is met so i wrote code like this

var bac         


        

Answer 1

Return a string if you want to offer an option to the user to abort the unload. Return nothing in other cases.

var back = false;
back = true; //Somewhere, the condition is set to true
window.onbeforeunload = function (e) {
    if(back == true)
        return "Are you sure to exit?";
}