userform textbox error trapping

Hello,
I have a userforum with several textboxes in them. My first textbox asks for a phone number. I want the user to only be able to enter numbers and after the first 3 numbers it automatically adds in a "-" and again after the next 3 then stops them form entering more numbers after 4 more, so it looks like ### - ### - ####.

I also have another textbox and I would like the user to be able to enter anyting except %&*@?:_-+= those symbols.

Thanks,

-Eric

Thanks Dave works like a charm