var wndUnloadText;
function checkUnload() {
	if ( !wndUnloadText ) return;
	return wndUnloadText;
}
function getWindowUnloadText() {
	return wndUnloadText;
}
function setWindowUnloadText( b ) {
	wndUnloadText = b;
	window.onbeforeunload = b?checkUnload:null;
}