Q:

Adding checked attribute via jQuery

I am using the following widget
http://www.erichynds.com/examples/jquery-ui-multiselect-widget/demos/
It has worked great so far, but I need some help in adding attributes. In using Firebug, I've noticed that by simply clicking on the checkbox the checked attribute does not appear as I would expect it to. In my code, I've modified the widget, I've been able to add code to remove the attribute of checked. 
this.removeAttribute(\'checked\'); this.checked=false;

if the item was checked beforehand. I've been successful in using this code
this.setAttribute(\'checked\', \'checked\'); this.checked=true; 

if the item was unchecked when the page loads. 
My problem is coming when I need to be able to utilize both sets of code on the checkbox, I've attempted the following
onclick="if($(this).attr(\'checked\') == \'true\') { this.setAttribute(\'checked\', \'checked\'); this.checked=true; } else { this.removeAttribute(\'checked\'); this.checked=false; }

the code will remove the attribute of checked (if checked before hand on page load), but when I attempt to click on the checkbox to add the attribute (if not checked on page load), nothing happens. 
Thanks for any help, and sorry for my poor coding.

A:

In jQuery for removing an attribute use 
this.removeAttr('checked');

and for setting an attribute use
this.attr('checked', 'checked');

A:

$(this).prop('checked',false)

or
$(this).prop('checked',true)

