Question

How can I validate a field only with upper case letters which are alphabetic. So, I want to match any word made of A-Z characters only.

Answer 1

Try something like this for the javascript validation:

if (value.match(/^[A-Z]*$/)) {
    // matches
} else {
    // doesn't match
}

And for validation on the server side in php:

if (preg_match("/^[A-Z]*$/", $value)) {
    // matches
} else {
    // doesn't match
}

It’s always a good idea to do an additional server side check, since javascript checks can be easily bypassed.