I shud giv som character/char's in the textbox

1.depend upon the key press it wil go n cal som jsp 2 get the
data(result set hav more than one line data)----from database here i
hav one doubt tht shal v cal jsp in key event functions....i'm not
getting....it......if anybody hav it plz fwd it.k.
2.After generate this jsp we wil get the data that i shud put into
dropdown list.For tht how shud i convert textbox as dropdown list after
generate the jsp...here i'm getting mainly 2 probs  a) how shud i
convert textbox as dropdown
         b) on the sam page n in the sam place i shud put tht dropdown
list ...
         c)How can v refresh the sam page?
I need this one urgently.....i need the requirement lik this...is it
possible..if yes...how cud i approach it? If No,any alternate 2 get it?
Plz ...help me...4 this