I need catch just windows close event [duplicate]

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• javascript detect browser close tab/close browser 8 answers

I need a javascript event that I can run a fuction when the user close the browser. I try to use "onBeforeUnload" but if I use jquey.onload (ajax) or refresh the page, javascript catch the event too. I only need run the funtion when the user close the browser. There are any form to do it??