[Eli-Hai]

$sql = "SELECT * FROM `tbl_name` ORDER BY `id` DESC";
$result = mysql_query($sql);

$num_rows = mysql_num_rows($result);

if($num_rows == 0) echo "Table don't exists";
else echo "Table exists";

תנסה לבדוק את זה ככה (בכוונה אל תוסיף mysql_error()).