crosstab - Mailing list pgsql-sql

Hi,
I don't know if it because I'm as sick as dog or I'm just a plain idiot - most 
likely a little of both.

Here is my table 

week_of date, 
item_number text,
planned_demand integer.

I have 
week_of        item_number      planned
2012-02-12    00005                200
2012-02-19    00005                -30
2012-02-26    00005                -16

I want to see

item_number   2012-02-12    2012-02-19   2012-02-26
00005                   200                 -30                 -16

I actually have added fields but that should get me started.

Thanks for help from an old man with a very bad cold.

Johnf