thanks
i found my old way which
search in file ./includes/functions.php about
$width_height = (!empty($image_info[3])) ? " ".$image_info[3] : "";
and replace it with
$width_height = (!empty($image_info[3])) ? " ".$image_info[3] : "";
$thumb = "<img onmouseover=\"pick(this)\" style=\"FILTER: alpha(opacity=80) gray()\" onmouseout=\"unpick(this)\" width=\"100\" height=\"80\" class=\"pic\" src=\"".$file_src."\" border=\"0\" alt=\"".$image_name."\" />";
change 100 width and 80 height to what ever you want
thanks