Hello, is there a way to add a close function in the tabs of the chat ares(the tabs that contain the name of the contact you're chatting with). I've checked the code, but I was confused? Which file should I edit and in which part???

See http://jqueryui.com/demos/tabs/ for how to use jQuery UI's tabs. At a glance, it looks like you will want to use the tabTemplate option to add a close button to the tab, and then handle the click of the close button to remove the tab. To remove a tab, there is a API call called remove().

All this work would be in gab.js. You'd probably want to modify the calls to .tabs('add',....).