Snippit: PHP: Validate U.S. phone Number

gistfile1.php

<?php
/*Validates if $phone is a valid U.S. phone number in the 202-555-1234 format. 
Note that the first didgit cannot be a 1 as no area code in the U.S. starts with a 1.
*/
function validatePhoneNo($phone) {
  if(preg_match("/^([1]-)?[0-9]{3}-[0-9]{3}-[0-9]{4}$/i", $phone))
     return true;
  else
     return false;
}
?>