Network functions problem

hello to all, I'm using windows 2000 with php 4.0.3 and I have found an email validator for an e-commerce site we are preparing. (see below) The problem is that the checkdnsrr function doesn't work at all. Anyone knows why or any way around this problem ....??? Thanks in advance. S function checkEmail($email, $check_dns = false) { if( (preg_match('/(@.*@)|(\.\.)|(@\.)|(\.@)|(^\.)/', $email)) || (preg_match('/^.+\@(\[?)[a-zA-Z0-9\-\.]+\.([a-zA-Z]{2,3}|[0-9]{1,3})(\]?)$/' , $email)) ) { if($check_dns) { $host = explode('@', $email); // Check for MX record if( checkdnsrr($host[1], 'MX') ) return true; // Check for A record if( checkdnsrr($host[1], 'A') ) return true; // Check for CNAME record if( checkdnsrr($host[1], 'CNAME') ) return true; } else { return true; } } return false; }