Form validation normally used to occur at the server, after the client had entered all the necessary data and then pressed the Submit button.
If the data entered by a client was incorrect or was simply missing, the server would have to send all the data back to the client and request that the form be resubmitted with correct information.
If the email addresses passes both these tests, then the function will return a true value.
The regex for validating the correct email format in line 2 has been borrowed and edited slightly by adding the i flag so that the regex is case-insensitive.
Here are some simple steps to make the process more secure.
Nothing exciting here except in line 6 where the on Click event is triggered when the user clicks on the button.This event will launch the verify Email() Java Script function which will check the user input of the email address.Here is the code for the verify Email() function: This function will return a false value if the user does not type in an email address in the correct format or if the user fails to type in the same email address in both fields.If the search() method returns a -1, then an alert would tell the user that an invalid email address has been entered and returns a false value.These functions check the validity of a UK postcode specified by the supplied parameter. The definition of a valid postcode has been taken from the official specification, and from the list of BFPO codes.
in uppercase and with a space between the inward part and the output parts.