层叠菜单的动态生成

if (isset($hierarchy)){
//$hierarchy[] = $selection;
if (isset($hierarchy)){
while(list($level, $sel) = each($hierarchy)){
echo "";
echo $level, ': ', $sel, "
n";
$nextlevel = (int) $level + 1;
}
}
}
else{
$nextlevel = 0;
}
echo "n";
for ($I = 1; $I echo "$In";
}
echo "n";
?>