PHP code -Create a Custom Exception Class

<?php
class customException extends Exception
{
public function errorMessage()
 {
 //error message
 $errorMsg = 'Error on line '.$this->getLine().' in '.$this->getFile()
 .': <b>'.$this->getMessage().'</b> is not a valid E-Mail address';
 return $errorMsg;
 }
}

$email = "someone@example...com";

try
{
//check if
if(filter_var($email, FILTER_VALIDATE_EMAIL) === FALSE)
 {
 //throw exception if email is not valid
 throw new customException($email);
 }
}

catch (customException $e)
{
//display custom message
echo $e->errorMessage();
}
?>