php身份证号码验证

    public function checkIdcard($vStr)
	{
	  $vCity = array(
	    '11','12','13','14','15','21','22',
	    '23','31','32','33','34','35','36',
	    '37','41','42','43','44','45','46',
	    '50','51','52','53','54','61','62',
	    '63','64','65','71','81','82','91'
	  );
	  if (!preg_match('/^([\d]{17}[xX\d]|[\d]{15})$/', $vStr)) return false;
	  if (!in_array(substr($vStr, 0, 2), $vCity)) return false;
	  $vStr = preg_replace('/[xX]$/i', 'a', $vStr);
	  $vLength = strlen($vStr);
	  if ($vLength == 18) {
	    $vBirthday = substr($vStr, 6, 4) . '-' . substr($vStr, 10, 2) . '-' . substr($vStr, 12, 2);
	  } else {
	    $vBirthday = '19' . substr($vStr, 6, 2) . '-' . substr($vStr, 8, 2) . '-' . substr($vStr, 10, 2);
	  }
	  if (date('Y-m-d', strtotime($vBirthday)) != $vBirthday) return false;
	  if ($vLength == 18) {
	    $vSum = 0;
	    for ($i = 17 ; $i >= 0 ; $i--) {
	      $vSubStr = substr($vStr, 17 - $i, 1);
	      $vSum += (pow(2, $i) % 11) * (($vSubStr == 'a') ? 10 : intval($vSubStr , 11));
	    }
	    if($vSum % 11 != 1) return false;
	  }
	  return true;
	}