How to check for alphabatical, numeirc values

hi all,
how to check for alphabatical, numeirc or any other before form get submit in php?

That can be done using javascript before the form is actually submitted. But if data security/integrity is an issue then you must also revalidate the form data when it is received by your php script after the form has been submitted. This is required because not all browsers will have javascript enabled and you cannot stop users from turning off javascript in their browsers or from attempting to send bogus data directly to your php script without using the form at all.

In the <form> tag, use the “onsubmit” attribute to trigger a javascript to run validation.

If you need more details, let me know