Confirm box before closing a tab

Question

I want to have a confirm box when user tries to close the window.

window.onbeforeunload = function (evt) {
    var message = 'Are you sure you want to leave, cause there are some unsaved changes?';
    if (typeof evt == 'undefined') {
        evt = window.event;
    }
    if (evt) {
        evt.returnValue = message;
    }

    return message;
}

The thing is I want to check a variables value

var sncro = 1;

If its value is not equal to one then this confirmation box should be there, else no need to have a confirmation. I'm not able to figure this. Its so silly but I request anybody can have a look on the code.

Related by for "navigating away" instead of closing: http://stackoverflow.com/questions/925734/whats-this-in-javascript-onclick Both solved with `onbeforeunload`. — Ciro Santilli OurBigBook.com, Jul 10 '14 at 21:44

score 1 · Accepted Answer · answered Mar 16 '10 at 08:42

1

I assume that on page load, you are setting up var sncro=1; and when some data changes, you adjust this value. Here is the quick check:

window.onbeforeunload = function (evt) {
  if (sncro != 1) {
   var message = 'Are you sure you want to leave, cause there are some unsaved changes?';
   if (typeof evt == 'undefined') {
      evt = window.event;
   }
   if (evt ) {
      evt.returnValue = message;
   }
   return message;
  }
}

answered Mar 16 '10 at 08:42

Fenton

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@Sohnee: I would consider using '!=='. What you have should work, but the concept of truth and implicit type conversion in js can be quite confusing. – Mads Ravn Mar 16 '10 at 08:48
@Mads Ravn - I agree with !== especially when comparing to 0 - but I never go too far down "JSLint" territory when talking about other people's code as you just never know where they decide to do blah = "1"; if (blah !== 1)... – Fenton Mar 22 '10 at 09:39
@Fenton - Can I write my own javascript code instead of this confirmation box. – Musaddiq Khan May 18 '17 at 07:49
2

Any specific method to use only on browser or tab close action rather than using on navigation ? – dipak_pusti May 24 '17 at 06:38

Confirm box before closing a tab

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