I want to point out to folks checking out this form validation that there are now several TLD's that have four or more letters. Some fo these TLD's have been around since Jan 2002, and still many form validations do not validate these email addresses correctly. Examples of these TLD's are .coop, .info, .name, .museum, .travel. I would suggest instead of validating by number of letters to actually download the TLD file from IANA (ftp://data.iana.org/TLD/tlds-alpha-by-domain.txt) and validate against the file. I know it may be more tedious, but for those of us in the 'unusual' TLD's it is frustrating to have to create a dummy account on excite, yahoo or hotmail, simply so we can pass form validation.