Validating form input with Java Script is easy to do and can save a lot of unnecessary calls to the server as all processing is handled by the web browser.It can prevent people from leaving fields blank, from entering too little or too much or from using invalid characters.Having the ability to lookup, verify, validate and check an email address is extremely important to many computer users.One of the most important reasons why consumers want to verify, validate and check an email address is to determine of email where you would like to send your message is "dead" or not.Checking an email address with our email checker is an important way to find out working and not working email addresses.From other side verifying email sender with our email tracking tool is important and can help you detect spam, fraudulent activity and identify spoof emails.Example: 22934 Returning false from the onsubmit event handler of the form stops the form being submitted.
This regular expression matches three groups of digits. ( # Capture the enclosed match to backreference 1... is another character class, one that allows any one of three separators.
Otherwise a browser with Java Script disabled, or a hacker trying to compromise your site, can easily submit invalid data. The first test in the example is therefore only necessary in order to provide a different error message when the input is blank.
The purpose of a form validation script is to return a boolean value ('s to reference form fields, but that can lead to namespace conflicts and why make things more complicated than necessary.
In the first line, I am using Element By Id() to grab the phone number from the input element.