Empty Or Not Check By Validation

I need to check each item in an array to see if it is empty or not. The array is created by a bunch of Request.Form's. I think I almost have it but I can't seem to get it right.

I need to check it, and if empty (null) I need to insert something. It can't be empty because it is used on an INSERT SQL thing. I would like it to be something like this:

A for loop running through each of the items in the array An if statement in the loop to check if it is empty or not. I haven't quite got down the If conditions in ASP.