User talk:Superthin

anybody could tell me why I met an error while typing : /script CastShapeshiftForm(1); in the chat box.

the error message is shown below:

[string "castshapeshiftform(1);"]:1:attempt to call global `castshapeshiftform' (a nil value)

I also tried some other API, but always met similar errors.

thank you very much!