I need to write a UDF to validate existing SSN in our system. We have found numerous SSN's with a character in the number. The numbers were imported from another system that did not validate the information.

I need to look at each position in the ssn and determine if it is a character or a number.

@ivalue = ASCII(SUBSTR(@cssn, @iposition, 1)

Then I look to see the value of @ivalue is between 48 and 57.

Any ideas?