I have an application developed in asp.net which set innerhtml of div. I am creating an html string to show googlemap. It works fine. But when I put my div inside update panel. it doesnt show googlemap in div. Here is my aspx file code:

            </td>
        </tr>
        <tr>
            <td colspan="4">
                <asp:UpdatePanel ID="UpdatePanel2" runat="server">
                    <ContentTemplate>
                        <div id="map_canvas" runat="server" style="width: 100%; height: 1500px; margin-bottom: 2px;
                            text-align: center;">
                            <asp:Panel ID="Panel1" runat="server">
                                <%--Place holder to fill with javascript by server side code--%>
                                <asp:Literal ID="js" runat="server"></asp:Literal>
                                <%--Place for google to show your MAP--%>
                                <div id="Div1" style="width: 100%; height: 728px; margin-bottom: 2px;">
                                </div>
                                <br />
                            </asp:Panel>
                        </div>
                    </ContentTemplate>
                    <Triggers>
                        <asp:AsyncPostBackTrigger ControlID="btnShow" EventName="Click" />
                    </Triggers>
                </asp:UpdatePanel>
            </td>
        </tr>

here is my button click event.

protected void btnShow_Click(object sender, EventArgs e)
{
  // works fine without update panel.     
  map_canvas.InnerHtml = showMapWithPoints();
}