I am creating a web user control which contains DropDown and TreeView if change the dropdown value the node is selected in tree control.
Page contains <cc1:scriptmanager xmlns:cc1="#unknown">
and web control use <asp:ToolkitScriptManager >
I got the error "Only one instance of a ScriptManager can be added to the page"
if I remove <asp:ToolkitScriptManager >from web user control then page is post back.
How can i stop the post back when change the dropdown value in web user control?