InfoPath Dev

I have a list on sharepoint which contains 2 columns. For example: column "product line" and column "E-mail" Then created a simple form with drop-down list box which takes values from "product line" column. What I want is to get in another text box the email address associated to selected product line. Please ...

I have a repeated table with the check boxes. Need to count all check boxes in a table which are tagged (true). Please, advice. thank you.