on Click .. check to see if is a value

[amfroehlich]

I have a table with two primary keys. I have a form with a 2 combo boxes being filled from that data. If my user click on a button on that form i am pulling up all of the data for that dual unique key. If not it is pulling up blank information. How can i make a button click event check to make sure the unique key is correct before loading the information?