>I found the following RegEx string to validate a zip code: "^\d{5}(-\d{4})?$"
>
>The following two string pass the test: 90210, 90210-1234. However, I need to make it accept the following string: 90210-.
>
>Any help would be greatly appreciated. From the little I know about regular expressions, I think there needs to be another optional clause added. Thanks!!!
>
>Edit:
>I changed it to the following and it seems to work: "^\d{5}(-)?(-\d{4})?$". Can somebody validate that I didn't do something silly? Thanks!

Yours will accept 12345--1234

^((\d{5}-?)|(\d{5}-\d{4})$

or

^\d{5}((-?)|(-\d{4})?)$