C#- Validation for US or Canadian zip code

Question

I am using following method to validate US or Canadian zip code, but i think it is not working fine for me. Please suggest me the changes in the regular expression.

Answer 1

If you are using Data Annotation Validators, you can use a RegularExpression attribute like this:

[RegularExpression(@"(^\d{5}(-\d{4})?$)|(^[ABCEGHJKLMNPRSTVXYabceghjklmnprstvxy]{1}\d{1}[ABCEGHJKLMNPRSTVWXYZabceghjklmnprstv‌​xy]{1} *\d{1}[ABCEGHJKLMNPRSTVWXYZabceghjklmnprstvxy]{1}\d{1}$)", ErrorMessage = "That postal code is not a valid US or Canadian postal code.")]

(regex is from the link @huMptyduMpty posted above at http://geekswithblogs.net/MainaD/archive/2007/12/03/117321.aspx but my regex allows both upper and lower case letters)