Pop up box showing once using cookies

Pop up box showing once using cookies

Hello Poeple!
I'm trying to do a small survey on exit using onbeforeunload function.
Now the jquery script for that works good, but once the page refreshes or the back button is pressed the pop up shows again. I'm trying to disable it using jquery cookies plugin.
This is my script so far, it doesn't seems to keep track of the cookies:

      $.cookie('appeal'); // get cookie
$.cookie('appeal', 'the_value'); // set cookie

function PopIt() 
{
if ($.cookie('appeal') == null) 
{
$.cookie('appeal', 'CookiePlus', { expires: 7 });
$("a#trigger").trigger('click');
window.onbeforeunload = UnPopIt;
return "Before you leave:\nPlease take a few seconds to answer 2 questions\nso we can better assist you and others in the future. \nThanks!";
}
else { }
}
function UnPopIt()  { /* nothing to return */ } 
 
$(document).ready(function() {
window.onbeforeunload = PopIt;
 
$("a#trigger").fancybox({
'hideOnContentClick': false,
'showCloseButton': true
});
 
$("a[id!=trigger]").click(function(){ window.onbeforeunload = UnPopIt; });
});

Hope someone can help me with this
Thank you!
Doron