Java Script provides a way to validate form's data on the client's computer before sending it to the web server. First let us see how to do a basic form validation.In the above form, we are calling validate() to validate data when onsubmit event is occurring.
By validating form responses before accepting them, we can alert users to their errors before they submit the form.
In this way, client side form validation can vastly improve the user experience.
This is validation to check that entered values are all letters or combination of different chars.
Following script will compile the idea of validation for all letters.
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.
This was really a lengthy process which used to put a lot of burden on the server.
When you submit a form to a CGI program that resides on the server, it is usually programmed to do its own check for errors.
If it finds any it sends the page back to the reader who then has to re-enter some data, before submitting again.
Now you can explore these areas and comment here in case of any issues.