Adobe XI form script for number with dash

I've been assigned to modify an adobe acrobat form where (1) filed needs to have a number with (2) leading numbers and a dash containing up to (5) more numbers. I formatted the field 99-99999, but found out that there is not always 5 characters after the dash. I guess it needs to be scripted to make this work.

So what I need to do is have a number like 99-9, 99-99, 99-999, 99-9999, and finally 99-99999


Can someone please help me with this?


Thank you in advance.


Kelly