Hi feirui445, there is a UI Mod that you can install that adds those buttons:

http://moi3d.com/forum/index.php?webtag=MOI&msg=6507.1
http://moi3d.com/forum/index.php?webtag=MOI&msg=6507.268
http://moi3d.com/wiki/MaxScriptArchive

- Michael