Ask Confirmation and autosave the page details before leaving

https://forums.asp.net/t/2113642.aspx?Ask+Confirmation+and+autosave+the+page+details+before+leaving

<script type="text/javascript">

var needToConfirm = true;
window.onbeforeunload = confirmExit;
function confirmExit() {
if (needToConfirm) {
$('[id*=btnSaveProjectDrafts]').click();
return 'are you sure you want to leave the page'?
}
}
</script>