Проверка email

//Работаем с e-mail
$email = savereplace($_POST['user_email']);
if ($email == ""){$er[] = "Вы не ввели e-mail";}
else{if (!check_email($email)){$er[] = "Вы ввели некоректный e-mail";} }
if (!isset($_POST['user_view'])){$view = "1";}
else{ $view = "0";}

FUNCTION savereplace($a) {
$a = str_replace("<", "{<}", $a);
$a = str_replace(">", "{>}", $a);
$a = str_replace(":", "{:}", $a);
$a = str_replace("\r\n", "{nl}", $a);
$a = str_replace("&nbsp;", "{sp}", $a);
$a = str_replace("<script>", "<s>", $a);
$a = str_replace("</script>", "</s>", $a);
$a = str_replace("@import", "'@import'", $a);
$a = str_replace("javascript", "'javascript'", $a);
$a = str_replace("style", "'style'", $a);
$a = bbcodessave($a);
return $a;
}

FUNCTION check_email($a){return preg_match('/^[a-z0-9]{1}[a-z0-9\-_]+@[a-z0-9\-_]+\.[a-z]{2,4}$/i', $a);}

function sp_c_m_s5($s){ return ereg_replace("[^a-z0-9]+(([a-z0-9_.-]+)?)@[a-z0-9+](([a-z0-9_.-]+)?)+\.+[a-z]{2,4}$","",$s); }