Return Authorization Module (RMA)

[Veronika7747]

trying to restrict order numbers to numeric I have modified this line as follows:

  if ($zc_validate_email and !empty($reason) and ($order_number !='' && $order_number == numeric)) {

		$send_to_email = RMA_EMAIL;
		$send_to_name =  STORE_NAME;

and added this:

	
	 if(ereg('^[\s0-9]*$', $order_number) === false){
    $error = true;
    $messageStack->add('returns', 'Order Number: Enter only numbers (must correspond to your order number).');
 }

It checks for numbers only fine, but when I enter numbers only, it does not send the form, but displays the filled in form again. What am I doing wrong?
Thanks