How to set tab-width to 4 spaces in emacs ??

[Thomas Weholt]

Trying to set the tab-width in emacs to 4 spaces without luck. Using
Mandrake 8.1 ( great distro btw, python 2.1.1, postgresql 7.1.3 etc. try it
now !)

tried :

# tab-width: 4
 etc. but no go.

Any hints ???

Thomas