Zwróć uwagę przed ponownym załadowaniem JS
<script>
// Warning before leaving the page (back button, or outgoinglink)
window.onbeforeunload = function() {
return "Do you really want to leave our brilliant application?";
//if we return nothing here (just calling return;) then there will be no pop-up question at all
//return;
};
</script>
Filthy Frog