creating a drop down menu from mysql categories

Hello everyone, I am a little new to the list. I have been reading a lot of the posts but have not submitted yet. But I ran into a problem I was hoping I might get e little help or at least get a point in the right direction. I have a table called tblCategories with field category_ID with is auto_incremented and another field called category_name. I wish to have a drop down menu on an html page that is generated automatically with Category_name as the option and the option value=category_ID. It is going in a form which I submit and adds to a mysql database. Everything is working fine except I cannot create the drop down menu out of php. I would rather not have to edit my html page when ever I add a category. Is there any place I can look to see how someone else has accomplished this? Or is there any specific function I should research in the php.net manual pages? I have been looking but not too successfull. thank you for any help you can offer. -chad