setting form values in rails?

[red]

hi!

i'm trying to build some stuff with RoR again and now got a little
problem and i hope someone can help me.

i've got the models securities, events ans allocations. there are
many_to_many relations between securities,events and allocations with i
made according to the rails recipes book (securities and events are
connected through the allocations with contains some extra data). now i
want to have a link in the events-listing that will redirect me to the
allocations-new where i'll just select the security and fill in the
extra data. now i can't fidure out how to pass the event_id to the form
and get error since the event_id must be set.

also it would be cool if i could set several allocations for one event
at the same time.

please help! - thanks

greetz
bernd forstner / red667