params colllection_select observe_field

Hi,

i have 2 dropdowns which are dependent from each other:
ItemCategory has many ItemGroups

if u use the same code in a form where i specify the action within the
form header, everything is good and i recieve the id from the
params-tag. But it is no tworking out of that observer - WHY? params is
always NIL!!!
If i debug it in FFBug, i can see the correct POST-Value...

I expect you'll find that the parameter simply doesn't have the name
you expect.
Look at the api examples and you'll see that if you pass :with =>
'something' to observe_field
then the observed value is stored at params[:something]. Can't
remember off the top of my head what the parameter name will be if you
don't specify :with (possibly just params[:value], but definitely not
params[:x][:id])

Fred