Adding an attribute to an HTML tag

Adding an attribute to an HTML tag

Hello! I'm trying to find a way to add an attribute inside an anchor. I want to do this is because that attribute is required by a script I have running on the page, but it is not valid.

Just so it makes more sense the code looks pretty much like this:
  1. <a id="previous" control="-6" href="#"></a>
and I would like to add control="-6" inside <a> via jQuery, only I don't know how.