mail and eregi problem

Hi, I'm having some trouble with this formToEmail script. It shuld take variables from html form, send them to me, and then send auto reply to the person who filed the form. But the problem is that, if the person dont enter e-mail, or enter "sjhdfzg" or leave empty, i receieve internal server error. I've looked for some functions, and found some eregi, that can cehck e-mail before sending. I just dont know how ti aply it. here is the code: <first mail> @mail($toemail, $subject, $linetot1, "From: $name <$email>\nContent-Type: text/plain; charset=windows-1250"); <second mail> The problem one with this function function validEmail($email) { if (eregi("^[a-z0-9]+([-_\.]?[a-z0-9])+@[a-z0-9]+([-_\.]?[a-z0-9])+\.[a-z]{2,4} ", $email)) @mail($email, $subject, $linetot2, "From: $toname <$toemail>\nContent-Type: text/plain; charset=windows-1250"); } Thanks!