Is there a way to make the category selecter automatically select the category currently being viewed?

Question

The specific information I am looking for is the php code to use when I want to use $this->output() to return the category id.

For example  /ask?cat=xx where xx is the category number.

Answer 1

This is already the case.

For example if you are on http://www.question2answer.org/qa/themes and click "ask question" it will automatically select the themes category.