[Haskell] Undefined of Char.toUpper ?

[Luo Shuli]

Dear Haskellers,
I am a beginer of the haskell language and study it from <<Yet Another
Haskell Tutarial>> of Hal Daume III.
Example  from the tutarial:
	Prelude> map Char.toUpper "Hello World"

I try it on Hugs for windows32, compile error:
       ERROR - Undefined qualified variable "Char.toUpper"

Could anybody tell me what's the matter with it?



Thanks,
Luo Shuli