cURL automatic login

Am trying to auto login at http://track.aasoftwares.net/pages/Premium_Tracking.htm

am trying the following cURL but i get no results:

<?php

//initiate curl process
$ch = curl_init();
$url = "http://track.futuresystems.co.ke/";

//set options
/*
There are a number of options, which you can use to manipulate
the behaviour of this ''invisible browser''.
See php.net/curl for more details.
*/

curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/My Test Browser");
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 10);
// ENABLE HTTP POST
curl_setopt ($ch, CURLOPT_POST, 1);

// SET POST PARAMETERS : FORM VALUES FOR EACH FIELD
curl_setopt ($ch, CURLOPT_POSTFIELDS, 'txtUserName3=******&txtPassword3=*****');

//run the process and fetch the document
$doc = curl_exec($ch);

//terminate curl process
curl_close($ch);

//print output
echo $doc;

?>

any help!