an example of how to check for just letters without preg_match in php

just_alphas.php

<?php
function isValid($string) {
    if (ctype_alpha($string)) {
        return true;
    } else {
        return false;
    }
}

// This returns true, just letters 
var_dump(isValid("LloydMoore"));

// This returns false, because of the space 
var_dump(isValid("Lloyd Moore"));

// This returns false
var_dump(isValid("Lloyd 2 Moore"));