PHP Curl post [savefrom.net]

Question

I am trying to get the download link from savefrom.net website, I am using the following code :

<?php
$agent = "Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax)"; 
$url = 'http://en.savefrom.net/savefrom.php';
$ckfile = dirname(__FILE__)."/c.txt";

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_COOKIEJAR, $ckfile);
curl_setopt($ch, CURLOPT_COOKIEFILE, $ckfile);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);  
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
$data['sf_url'] = "http://www.dailymotion.com/video/x34uoat_hero-behind-the-scenes-part-1-making-of-the-trailer_shortfilms";
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_REFERER, 'http://en.savefrom.net/');


$output=@curl_exec($ch);
$info = @curl_getinfo($ch);

$header_size = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
$header = substr($output, 0, $header_size);
$body = substr($output, $header_size);
//echo "<h1>body</h1><br>".$body . "<h1>Header</h1><br><br>" .$header ;


if(curl_errno($ch)){
  echo 'Curl error: ' . curl_error($ch);
}

curl_close($ch);
echo "output is:'" . $output . "'";
echo "<br>";
echo "<h2>info is:</h2>";
print_r($info);
?>

so far the code runs but it gives me alert messagbox which says : goto the website for direct download link!!!. Am i doing something wrong in the code. Is there any alternative way to get video download link from website like dailymotion etc. Thanks for your time

regards