Contact Field Set Up Problem

We (as a whole) have decided it would be a good idea to have a way for administration to be able to reach the members in case of emergency.  So, I tried to add a contact field - telephone.  It LOOKED as though it went in OK, but the execution is a different story.  When I try to fill in the field in my profile, it tells me I MUST fill in information, etc, etc.  Problem is, I DID fill it in.  There seems to be no option to make the field contents numbers - it shows 'text'.  How do I set up a profile field that takes numbers??  It will be a required field for all members, and not visible to anyone other than the individual member or admin.

Thanks for the help!

Nevermind.  It wasn't the PHONE field that was the problem.