Someone

<?
$num = (int) $HTTP_GET_VARS['n'];
$num++;
if ($num > 2500){
$num = 2500;
}
for($n = 1; $n < $num; $n++) { 
for($a = 1; $a < $n; $a++) { 
   echo ".";
} 
echo "\ <br>";
} 
for($n = $num; $n > 1; $n--) { 
for($a = 2; $a < $n; $a++) { 
   echo ".";
} 
echo "/ <br>";
} 
?>