Просмотр файла ad.php

<?php

$id = "1";
function show_ads($id)
{
$get = 'http://localhost/project/index.php?ac=ads&id='.$id;
$advertisement = file_get_contents($get);
print $advertisement;
}

?>
<?php
// put this code anywhere of your site to print ads
echo show_ads($id);
?>