If you are editing your site design using the old "Look & Feel" system, then you should see an area for updating your "Header":

http://edit.xanga.com/claf.aspx

You can choose to "Hide Header" completely, use Xanga's WYSIWYG tools to "Create a Custom Header", or even "Input your own Header HTML".

(Please note: there are some security concerns with allowing certain types of Javascript, so we've had to disable some of the Javascript functionality that can be used in your Javascript module. If you've added some code that isn't working, it's possible that that specific code just isn't allowed.)