Problem with list box

[lal.jagdish]

Hello,
I have two listbox when i clicked items from one listbox
the other one gets populated list box but when it gets autopostback to
the server the page jumps or refresh that i get confused.

so what i have to do is i wanted stop autopost back but when i select
the first dropdown the other should be populated without get the
autopost back i.e without refereshed the page. or server control

Please help me to get this out