InfoPath Dev

I need to create a calculated text field based on two other Combo box on the form The problem is that if another selection is made in the Combo box the text field does not change accordingly since its a sharepoint list form i cant use code behind and because there is no such thing as an if statement i cant set it as a default value thank you for any help

Welcome to the forum.

So you've told us that you want to combine two fields into another field, but you haven't told us how you want to combine them. Where would an if statement figure into the situation, and why is a default value formula problematic?