Moving items from one listbox to another listbox...please read my requirement

Hi,

friends

I have a requirement in my site that is

I have two tables that is main branch and subbranch
main branch table contain businessid and businessname columns

subbranch table contain businessid and subbranchid and subbranchname

in this businessid in mainbranch table primarykey and subbranch table forienkey...

i have a list box in that listbox i attached businessname and subbranchname according to businessid as a treestructure
that is businessname is parent and subbranchname is child like wise i attached some items

actually my requirement is if i select anyone that is parent or child that will be moved to another list box ....
if i select parent and click button that businessname and subbranchname will be moved to another list box

ex

listbox1 listbox2

+mainbranch1 +mainbranch1
-subbranch1 - subbranch1
+mainbranch2
-subbranch2 >>

if i select mainbranch1 and click on the button that will be moved to another listbox see above......

please give me the code for this one any one can help me ....please........................

alredy i search i am not getting relevent code for this one....please give me the code.......