gridview inside update panel is not working - asp.net

Question

i have some imagebuttons in GridView and when i clicked those image buttons whole page is refreshed. i just want to fire that image button event when i click to that imagebutton without reloading whole page. i have also used updatepanel.
i am facing this problem from two days now i need help i thing i cant do this.
this is my .aspx
<asp:ScriptManager ID="ScriptManager1" runat="server" EnablePartialRendering="true" ></asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="updatebutton" EventName="Click" />
</Triggers>
<ContentTemplate>
<asp:ImageButton ID="updatebutton" runat="server" Visible="false" OnPreRender="ImageButton_PreRender" OnClick="ImageButton_Click" />
<asp:GridView ID="gvSeatLayout" runat="server" AutoGenerateColumns="False" Width="755px" AllowPaging="True"
OnRowDataBound="gvSeatLayout_RowDataBound" OnRowCreated="gvSeatLayout_RowCreated"
PageSize="25" ShowHeader="False" CellSpacing="0" CellPadding="5" BorderStyle="None" >
<RowStyle CssClass="gvspace" />
<Columns>
<asp:TemplateField>
<ItemTemplate>
<table>
<tr><td>
<asp:LinkButton ID="LinkButton1" Enabled="false" Font-Bold="true" ForeColor="White" CommandName="lbtnRowId" CommandArgument='<%# Eval("RowId") %>' Text='<%# RowName(Eval("RowName").ToString()) %>' runat="server"></asp:LinkButton>
</td>
</tr>
<td></td></table>
</ItemTemplate>
<ItemStyle BorderStyle="None" />
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:ImageButton ID="ImageButton1" CssClass="ss" OnClick="ImageButton_Click" CommandArgument='<%# Eval("L1") %>' CommandName="ib1" runat="server" ImageUrl='<%# MyUrl(Eval("L1").ToString(),Eval("RowId").ToString()) %>' />
<asp:PopupControlExtender ID="PopupControlExtender1" runat="server" popupcontrolid="Panel1"
targetcontrolid="ImageButton1" dynamiccontextkey='<%# Eval("L1") %>' dynamiccontrolid="Panel1"
dynamicservicemethod="GetDynamicContent" position="Bottom">
</asp:PopupControlExtender>
</ItemTemplate>
<ItemStyle BorderStyle="None" />
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:ImageButton ID="ImageButton3" runat="server" CssClass="ss" OnClick="ImageButton_Click" CommandArgument='<%# Eval("L3") %>' CommandName="ib3" ImageUrl='<%# MyUrl(Eval("L3").ToString(),Eval("RowId").ToString()) %>'/>
<asp:PopupControlExtender ID="PopupControlExtender2" runat="server" popupcontrolid="Panel1"
targetcontrolid="ImageButton3" dynamiccontextkey='<%# Eval("L3") %>' dynamiccontrolid="Panel1"
dynamicservicemethod="GetDynamicContent" position="Bottom">
</asp:PopupControlExtender>
</ItemTemplate>
<ItemStyle BorderStyle="None" />
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:ImageButton ID="ImageButton4" runat="server" CssClass="ss" OnClick="ImageButton_Click" CommandArgument='<%# Eval("L4") %>' CommandName="ib4" ImageUrl='<%# MyUrl(Eval("L4").ToString(),Eval("RowId").ToString()) %>'/>
<asp:PopupControlExtender ID="PopupControlExtender3" runat="server" popupcontrolid="Panel1"
targetcontrolid="ImageButton4" dynamiccontextkey='<%# Eval("L4") %>' dynamiccontrolid="Panel1"
dynamicservicemethod="GetDynamicContent" position="Bottom">
</asp:PopupControlExtender>
</ItemTemplate>
<ItemStyle BorderStyle="None" />
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:ImageButton ID="ImageButton8" runat="server" CssClass="ss" OnClick="ImageButton_Click" CommandArgument='<%# Eval("U1") %>' CommandName="ib8" ImageUrl='<%# MyUrl(Eval("U1").ToString(),Eval("RowId").ToString()) %>'/>
<asp:PopupControlExtender ID="PopupControlExtender4" runat="server" popupcontrolid="Panel1"
targetcontrolid="ImageButton8" dynamiccontextkey='<%# Eval("U1") %>' dynamiccontrolid="Panel1"
dynamicservicemethod="GetDynamicContent" position="Bottom">
</asp:PopupControlExtender>
</ItemTemplate>
<ItemStyle BorderStyle="None" />
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:ImageButton ID="ImageButton10" runat="server" CssClass="ss" OnClick="ImageButton_Click" CommandArgument='<%# Eval("U3") %>' CommandName="ib10" ImageUrl='<%# MyUrl(Eval("U3").ToString(),Eval("RowId").ToString()) %>'/>
<asp:PopupControlExtender ID="PopupControlExtender5" runat="server" popupcontrolid="Panel1"
targetcontrolid="ImageButton10" dynamiccontextkey='<%# Eval("U3") %>' dynamiccontrolid="Panel1"
dynamicservicemethod="GetDynamicContent" position="Bottom">
</asp:PopupControlExtender>
</ItemTemplate>
<ItemStyle BorderStyle="None" />
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:ImageButton ID="ImageButton11" runat="server" CssClass="ss" OnClick="ImageButton_Click" CommandArgument='<%# Eval("U4") %>' CommandName="ib10"
ImageUrl='<%# MyUrl(Eval("U4").ToString(),Eval("RowId").ToString()) %>'/>
<asp:PopupControlExtender ID="PopupControlExtender6" runat="server" popupcontrolid="Panel1"
targetcontrolid="ImageButton11" dynamiccontextkey='<%# Eval("U4") %>' dynamiccontrolid="Panel1"
dynamicservicemethod="GetDynamicContent" position="Bottom">
</asp:PopupControlExtender>
</ItemTemplate>
<ItemStyle BorderStyle="None" />
</asp:TemplateField>
</Columns>
<FooterStyle BorderStyle="None" />
<SelectedRowStyle BorderStyle="None" />
<EditRowStyle BorderStyle="None" />
<AlternatingRowStyle BorderStyle="None" />
</asp:GridView>
</ContentTemplate>
</asp:UpdatePanel>

Answer 1

Try change the update mode to "Always". At the moment, the Async method is tied with the "updatebutton".

Answer 2

Try to place the triggers tag after the content template end tag like this...
...</ContentTemplate> <Triggers> <asp:AsyncPostBackTrigger ControlID="updatebutton" EventName="Click" /> </Triggers>