how should I be handling validation for this?

two listview controls on the same page... one supporting edit, delete, and insert, and the other one supporting edit/delete. All that functionality is working fine. I just went to add some input validation and ran into this problem:
added  a required field validator for a textbox control used for the 'insert', tested, worked fine... then I went to the second listview, attempted an edit/update and the required field validator from the first listview fired! ... I get why that happened, the textbox controls for the insert on the first listview are always visible, so the validator kicks in on any postback. So how do I handle setting up validation for both of these listviews on the same page? 
...