Populate DataGrid while selecting TreeNode

[Satiz]

Hi All,
I've a TreeView(IE Webcontrol) and a DataGrid in my VS.Net 2003 ASP.Net web form.
My problem :
If i select a particular node(it may be parent, child or leaf), then the corresponding values from a dataTable should be displayed in the DataGrid. I've a code-behind function for LoadGrid(), this is calling selecting a node and clicking a button only, I want to load grid while selecting a node. Pls give me the codes and ideas to do, it's urgent.............