window.onbeforeunload = function () {
    return 'message'
};

var tempDisableBeforeUnload = function() {
    var obu = window.onbeforeunload;
    if (obu) {
        window.onbeforeunload = null;
        setTimeout(function() {
            window.onbeforeunload = obu;
        }, 0);
    }
}
$("form.noWarnOnSubmit").submit(tempDisableBeforeUnload);