PHP Error Handling

Testing the error handler by trying to output variable that does not exist:

Code:
<?php
//error handler function
function customError($errno, $errstr)
  {
  echo "<b>Error:</b> [$errno] $errstr";
  }

//set error handler
set_error_handler("customError");

//trigger error
echo($test);
?>

Output: Error: [8] Undefined variable: test