Help!!! Very wet behind the ears as far as all this is concerned...

I've created a stored procedure to insert data into a database table (Buildings)-- one of whose fields is a foreign key ID field to another table (Locations). All I'm trying to do is create an ASP form that will allow the user to insert records into the table relating to the Buildings, but will allow them to select the relevant Location from a dropdown list (supplied by another stored procedure). I'd then like to use that "answer" to be the ID integer for the locationID in the Buildings table. Trouble is, I'm getting in a tizz, 'cause I can't get my head (or my server behaviours) around it.

Anyone got any ideas???