/** send headers **/
 function send()
 {
     global $sendheaders, $sendnocacheheaders, $gzip;
     if ($sendheaders == 1) {
         @header("HTTP/1.0 200 OK");
         @header("HTTP/1.1 200 OK");
         @header("Content-type: text/html");
     }
     if ($sendnocacheheaders == 1) {
         @header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
         @header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
         @header("Cache-Control: no-cache, must-revalidate");
         @header("Pragma: no-cache");
     }
     if ($gzip == 1) {
         headers::compress();
     }
 }