[Solved] Tree nodes collection becomes null

[Priya]

Hi Telerik,

I am adding nodes to a treeview dynamically on a button click event. Am calling the controller on button cick using javascript. In the controller have a value in ViewData. Then it returns to the View. And  on pageload, if ViewData value is true, am adding nodes to the treeview. I am able to add one node. Then when i again click on the button to add another node, the node list is empty and first node gets replaced by this. 
Please help me on this.

Thanks