Combo box user selection sent to a different table..Help

Question

Hello everyone; I have a Win Form that has 2 combo boxes on it. Each of these boxes is filled with elements from two different tables. I am using SQL Adapters, Connections, and Data Sets to accomplish this. What I am attempting to do is to have the user select an item from each of the combo boxes, push an update button and fill a third table with the user selected information from the combo boxes...For example I have a pet name in the first combo box and a vet name in the second combo box...I want to combine the two into one table so that eventually I can add a calender to the form and have an appointment for the pet, with a vet, on a particular date. Am I going about this all wrong? How should I send the selected index from each of the combo boxes to the third table? Any thoughts or suggestions from anyone??? I am still fairly new to C#...so please bear with me!!!! THANKS!!!!