First, your HTML is invalid. You've got a form that is opened in one table cell and closed in another (can't do that... wrap the entire table in the form tag instead). The first thing you should do is clean up the validation errors. [validator.w3.org...]
Next, I would look more closely at your logic. It seems as though you're trying to do too much with a single function. For example, the first select box is where you pick the person only. The second is where you pick the sport only. Yet you're trying to use a single function to handle both cases, which just over complicates the problem.