Exactly how did you define your value list?
What format do your four fields have Radio buttons? Check boxes? Drop Down List? Pop-up Menu?
Ohhh Phil, I'm sorry for delay in my reply.
I didn't received subscrition's mail to this post, so just now i read your gentle message.
I apologize yet.
My list is a "Drop Down List".
However I solved the problem with a script associated to one button.
The script I used is a simple "Delete" function. Simply it targets to the field with the "value list" and to clear it.
More simply than i thought.
Thanks for your helps.