Can anyone help me write proper validation for validating a domain name (only SLD), I am trying few things wit RegEx but guess I am not very comfortable with regular expressions now. The conditions for valid domain mae are as follow - * Domain Name must be composed of the letters a through z, the numbers 0 through 9, and the hyphen (-) character. * The Domain Name must not begin or end with the hyphen character. * The Domain Name must not contain spaces. * The Domain Name must not contain special characters other than the hyphen character. * The Domain Name must contain 2 to 63 characters, inclusive. * Domain Names are not case sensitive. What should I put in this mask now considering the conditions mentioned above? mask ???????? TIA, - Manish

The following regexp will cover everything but the length check, which can be done by adding minlength and maxlength clauses to the validation rule (Covered in the validator docs). ^([a-zA-z0-9]{2,})(-([a-zA-Z0-9]+))*$

Thanks!!! It almost works perfect, but it takes an uderscore as a vaild inpits which is incorrect. Besides alpha-numeric characters, I only want hyphen to be accepted. - Manish

Hmmm, Oops, I made a slight typing mistake in the original regular expression - the second 'z' should be uppercase. The typo means that anything between uppercase 'A' and lowercase 'z' will be allowed in the section before the first '.' - and this would include any of the following characters... [\]^_` My apologies for any extra time that you wasted looking for my typo. Just for the record, here is a link to a great tool that allows you to do 'what-if' experiment with regular expressions, this really helps you to practice using them - something that you should be doing because they really do make you code easier to read (and adjust) http://www.weitz.de/regex-coach/ Enjoy!

Thanks a ton for the useful link! :) - Manish