<?
$num_of_html = 1;       
$html_dir    = "папка";
$html_tip    = ".html";

// =======================================================

$html_array = array();
$d = dir($html_dir);
while($entry=$d->read())
{
     if(ereg("html$",$entry))
     {
         $html_array[] = $entry;
     }
}
$d->close();

srand ((double) microtime() * 10000000);
$rand_keys = array_rand($html_array,$num_of_html);

echo "<table align=center cellpadding=0 width=150 cellspacing=0 border=0>";
for($m=0;$m<$num_of_html;$m++)
{
  echo "<tr><td>";
  if($num_of_html==1)
  {
    include($html_dir."/".$html_array[$rand_keys]);
  }
  else
  {
    include($html_dir."/".$html_array[$rand_keys[$m]]);
  }
  echo "</td></tr>";
}
echo "</table>";

?>