$ba = mysql_query("SELECT * FROM ad WHERE user='".$user."'") or die (mysql_error());
$ba = mysql_fetch_array ($ba);

for ($i=0; $i<mysql_num_rows($ba); $i++) {

echo "<a href=\"".$ba['url_site']."\"><img src=\"".$ba['url_img']."\" width=\"120\" /></a>
";  

}