Error message didn't popup

Hi all
When I try show an error message with this code (on validate event):


	if ($codobra!={CodigoObra})
	{
           $error_message = 'Field1 must be different from some_value.'; // Error message
     	   sc_error_message($error_message);
	   sc_error_exit();
	}

Only display “Error”…

ScriptcaseError.png

I answered you on Google+. It works for me. More data is needed.