Button控制PopupControlExtender，但为什么Button的onclick事件不响应了啊该怎么处理

Button控制PopupControlExtender，但为什么Button的onclick事件不响应了啊？
如题：
具体使用如下..
<asp:Button   ID= "btnDelReceiver "   runat= "server "   Text= "... "   OnClick= "btnDelReceiver_Click "     />

<ajaxToolkit:PopupControlExtender   ID= "PopupControlExtender2 "   runat= "server "   PopupControlID= "Panel3 "   OffsetX= "20 "
                  Position= "Left "   TargetControlID= "btnDelReceiver "   BehaviorID= "ctl00_PopupControlExtender2 "   DynamicServicePath= " "   Enabled= "True "   ExtenderControlID= " ">
                </ajaxToolkit:PopupControlExtender>
此时btnDelReceiver_Click不响应，请问如何解决？


------解决方案--------------------------------------------------------
没用过微软的ajax控件