treeview control

i am having one treeview control ,in that treeview control i am having parentnodes,childnodes.when i select that childnode i want display some controls
where i have to write code

You could add the event handler code for the click or doubleclick event of the treeview

Ex:
if treeview is named 'tv1' you could write the following code to get the currently selected child node

tv1.SelectedNode.text

Use the return for the above code in a select case statement to write your eeded code.

a case when a problem can arise is when nothing is selected in treeview
you can handle that using the followin code

If TV1.SelectedNode Is Nothing Then
' Your code here
end if

Hope that this will be of help