21段救命PHP代码(3)

                foreach($email as $e)
                {
                                $encoded .= "document.write('$e');";
                }
                $encoded .= "document.write('$part3');";
                foreach($linkText as $l)
                {
                                $encoded .= "document.write('$l');";
                }
                $encoded .= "document.write('$part4');";
                $encoded .= '</script>';    
        
                return $encoded;
        }

4. PHP验证邮件地址
　　电子邮件验证也许是中最常用的网页表单验证，此代码除了验证电子邮件地址，也可以选择检查邮件域所属 DNS 中的 MX 记录，使邮件验证功能更加强大。
        function is_valid_email($email, $test_mx = false)
        {
                if(eregi("^([_a-z0-9-]+)(\.[_a-z0-9-]+)*@([a-z0-9-]+)(\.[a-z0-9-]+)*(\.[a-z]{2,4})$", $email))
                        if($test_mx)
                        {
                                list($username, $domain) = split("@", $email);
                                return getmxrr($domain, $mxrecords);