Blogger problem with reciprocal script

[grigione]

Hello i'm using this script to search a specific piece of html code in webpages:

<?php
$website = $_POST['url'];
$siteurl = $_POST['recurl'];
$recip = '<!-- Start Backlink Code --><a target="_blank" href="http://site.com" title="Site"><img border="0" src="http://site.com/image.gif" alt="Site"/></a><!-- End Backlink Code -->';


if (backlinkCheck($siteurl, $recip) === TRUE) {

  echo "Backlink was FOUND on: ".$siteurl;

} else {

  echo "Backlink was NOT FOUND on: ".$siteurl;

}



function backlinkCheck($siteurl, $recip) {

  $content = file_get_contents($siteurl);

  if(strpos($content, $recip) !== FALSE){

    return TRUE;

  } else {

    return FALSE;

  }

}

?>

 

This script working very well but if  I insert my piece of code in blog of blogspot/blogger in particular in  gadget of blogger ( html/ javascript gadget) the script don't find code

If i insert my piece of code in posts of blogger script find code  but in gadget no 

Where is the problem?

Thanks