Create popup after server side validation

[Joe90]

Scenario: We have a TreeView on our website that when a user clicks a leaf a
new browser opens displaying a report in a ReportViewer.

However, on clicking the TreeView we need to do some server side validation
BEFORE calling the Client side script to generate the popup.

We can do the server side validation and the client side script individually
but we can't work out how to do them both sequentially.

Any help would be appreciated.

 

[Mike]

Would you mind telling me how you were able to link the treeview to the reportviewer?

Thank you!