Have you declared the
ScriptManager
or
ToolkitScriptManager
control in your page before declaring your
AjaxControlToolKit
ComboxBox
? You should have something like this in your page:
<asp:ToolkitScriptManager runat="server"></asp:ToolkitScriptManager>
That is one special requirement when using the controls from the AJAX Control Toolkit. The page must contain a
ScriptManager
/
ToolkitScriptManager
control as this control is responsible for including all of the necessary
JavaScript
required by the AJAX Control Toolkit controls.