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.
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.