I'm trying to let the user set their preference on a scale of 0 to 5.  Something like:

Pref 1  ***** select rating

Pref 2 ***** select rating

Pref 3 ***** select rating

 After they make a selection I want to remove a star from the other unselected rating controls.  So in other words the rating values can only be used once.  How can I accomplish this?

I used a custom validator instead to make sure the current rating wasn't used more than once.