Server side form validating numbers
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.
Server-side validation is enough to have a successful and secure form validation.
For better user experience, however, you might consider using client-side validation.
In client side validation the data is validated in the browser using Java Script before submitting the data to the server.