Stichoza/email_username_validation.php

## email_username_validation.php
<?php
function is_valid_email($s) {
    return preg_match('/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/', $s);
}
function is_valid_username($s) {
    return preg_match('/^[A-Za-z0-9-_]+$/', $s);
}
?>
	<?php
	function is_valid_email($s) {
	return preg_match('/^[_a-z0-9-]+(\.[_a-z0-9-]+)@[a-z0-9-]+(\.[a-z0-9-]+)(\.[a-z]{2,3})$/', $s);
	}
	function is_valid_username($s) {
	return preg_match('/^[A-Za-z0-9-_]+$/', $s);
	}
	?>