wp-advanced-search | PHP framework for building advanced search forms | Content Management System library

ID's need to be unique, but you're using the same IDs for the checkboxes in each DIV. In my code below, I've changed the IDs of the checkboxes to have a different prefix in each DIV.

Also, $$.is(':checked') doesn't work on a label, that property belongs to the associated checkbox. But you don't need to check the checkbox in your code, that happens automatically because you have the for attribute in the label. When the code checks the checkbox, it then gets unchecked when the click event goes to the checkbox.

Note that putting the event handler on the label means you only get the highlighting when the user clicks on the label, not when they click on the checkbox itself. You can solve that by either putting the event handler on the checkbox and then adding the class to the label sibling, or by wrapping the label around the checkbox instead of making them siblings.