Selenium select element with multiple attributes

Question

How do I select a div using both it's id and class in Selenium firefox addon?

EDIT: I managed to solve it, I used an xpath expression with both the attributes @id= and @class =

Answer 1

I stumbled upon this question and thought I would leave an example of the answer that the OP didn't leave (as requested by vincebowdren above):

//*/fieldset[@class="openable"][@id="activityFieldset"]

This would select a fieldset element with the openeable class and activityFieldset id.