global-set-key [tab] doesn't work

[Robin Wilson]

Hi

I'm sorry to keep asking questions, but I can't seem to find the answers 
to most of these things elsewhere, and you've been very helpful so far. 
As I said - after learning all of that hopefully I'll be able to help 
other people.

Basically in my .emacs file I have the following lines:

(global-set-key [tab] 'indent-or-complete)
(global-set-key [C-z] 'undo)

but neither of these work when used in a buffer. If I type, for example, 
(def and press TAB it does nothing, but if I do M-x indent-or-complete 
it completes it to (defun. TAB however does indent properly when used on 
a blank line. I'm guessing from this that the binding hasn't been set 
properly - but I'm not sure how I set it properly! I've copied the 
bindings I've used for Function Keys (F1, F2 etc) and assume it's the 
same syntax.

The same thing occurs with C-z binding to undo. If I do M-x 
global-set-key and then press C-z and type undo it works fine.

Any ideas anyone?

Cheers,

Robin