Email validation

Google is a really useful tool.

http://www.w3schools.com/js/js_form_validation.asp

If this is just for learning, you can also use the email input type in HTML5 which validates it. If you are doing this just through HTML4 and JavaScript look at using Regex. The example above is terrible.

http://stackoverflow.com/questions/46155/validate-email-address-in-javascript

http://www.regular-expressions.info/email.html

http://www.w3schools.com/js/js_obj_regexp.asp

You should try matching against this expression to check if valid characters were entered for an email address:

/^[\w\-\.\+]+\@[a-zA-Z0-9\.\-]+\.[a-zA-z0-9]{2,4}$/

Check out the .match() function. I don't want to completely give you the answer on this.

http://stackoverflow.com/questions/46155/validate-email-address-in-javascript

Should show an error message if they enter invalid domain name.

How far do you want to take this? For example, what jwmollman posted does not allow .museum. It does allow .xx which is not a valid extension (yet). I advise to fully read the second linke stbuchok provided. What about arabic domains?

Any budy know about how to perform ajax (email already exist) validation in jsp