94215 Little Oscommerce work

On a Oscommerce site I use the shipdate contribution to let customers select a date when they want the order to arrive. This "calender" is up on the [login to view URL] page. But I only want to use the calender when customers have a item in his/her shopping cart from a specific categorie(s). If not from specific category the don't use the calender. Probarly a good if/else statement is enough but my PHP knowledge is to poor for this..........I have a testsite so you can make it "live" (and I can test it). regards, Chris de Jong