JS Error on my portal

I wouldn't remember what has been changed on my portal but

here is my web url:
http://www.u-down.co.il

and as you can see , the portal is working great on IPB 3.1.4 expecting of some issues that should be fixed.
JS error is annoying me when I am browsing on this web, it would be nice to get your solution here.

Message: 'undefined' is null or not an object
Line: 867
Char: 128
Code: 0
URI: http://www.u-down.co.il/public/min/index.php?ipbv=31007&charset=UTF-8&f=public/js/ipb.js,public/js/ips.quickpm.js,public/js/ips.topic.js,public/js/ips.uportal.js,public/js/ips.signin.js,cache/lang_cache/6/ipb.lang.js

I found this code:

{parse js_module="uportal"}

When remove this code, nothing will be changed on your website and you won't be able to minimize or maximize the categories,
but when adding this code, this will show this error above and won't let you continue browsing quietly.



I went to: public/js/ips.uportal.js and found:

if( cookies[ abcdefg ] )
				{
					var wrapper	= $( 'category_' + cookies[ abcdefg ] ).up('.category_block').down('.table_wrap');
					
					wrapper.hide();
					$( 'category_' + cookies[ abcdefg ] ).addClassName('collapsed');
				}

Remove this code and you'll never get an error message! If you guys have another way of fixing that issue, let me know that!

Solution: Replace:

if( cookies[ abcdefg ] )

with:

if( cookies[ abcdefg ] > 0 )