event for the closingof the browser

i am having a a开发者_如何学Gosp.net and c#.net application and i have a page gridview.aspx which has a button "close".

when a person closes the browser page by clicking the close icon in the top right of the browser i want to perform the click event of the "close" button,

do we have any event beforebrowserclose()?

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No.

WebForms applications use PostBacks to fire off Events. Since the browser doesn't do a PostBack before it closes, there's no way to wire an Event for that.

Unfortunately there's not even a reliable, cross-browser way to accomplish this in Javascript either.

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function clickclosebtn() {

        if (window.event.clientX < 0 || window.event.clientY < 0) 
    {

        document.getElementById("<%= btnClose.ClientID %>").click(); 
    }

    }