This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Window.onbeforeunload is working only when it is has return value

  • 1 reply
  • 6 have this problem
  • 64 views
  • Last reply by guigs

more options

Problem statement is want to execute piece of code only on browser close , refreshing the browser tab , tab close .

Previous version of firefox used to execute the code in window.onbeforeunload in all the 3 events mentioned above but now code in window.onbeforeunload is not executing on refresh click and browser close .

based on the discussion with previous ticket i kept return statement in this block . Now i am able to see the confirmation box . But now i want to execute the code only when we click on Leave this page.can you please help on this . Thanks alot.

One more observation is if i keep the code in window.onunload code is not executing in the tab close and browser close but it is executing in the on refresh .

Problem statement is want to execute piece of code only on browser close , refreshing the browser tab , tab close . Previous version of firefox used to execute the code in window.onbeforeunload in all the 3 events mentioned above but now code in window.onbeforeunload is not executing on refresh click and browser close . based on the discussion with previous ticket i kept return statement in this block . Now i am able to see the confirmation box . But now i want to execute the code only when we click on Leave this page.can you please help on this . Thanks alot. One more observation is if i keep the code in window.onunload code is not executing in the tab close and browser close but it is executing in the on refresh .

Modified by BalajiPolisetty7

Chosen solution

Hi, I admire your persistence on this question however there is a bug that has the attachment that Gingerbread man referred to titled: "Bug 391834 - Don't allow alert/confirm/prompt in onbeforeunload, onunload and onpagehide"

This sounds like its disabled and you are trying to make it work. But you also already solved this with a batch file in this question https://support.mozilla.org/en-US/que.../993972?esab=a&s=&r=0&as=s So I will mark this as resolved.

Read this answer in context 👍 0

All Replies (1)

more options

Chosen Solution

Hi, I admire your persistence on this question however there is a bug that has the attachment that Gingerbread man referred to titled: "Bug 391834 - Don't allow alert/confirm/prompt in onbeforeunload, onunload and onpagehide"

This sounds like its disabled and you are trying to make it work. But you also already solved this with a batch file in this question https://support.mozilla.org/en-US/que.../993972?esab=a&s=&r=0&as=s So I will mark this as resolved.