image button inside the panel is not firing onclick event

<asp:Panel ID="Panel1" runat="server" CssClass="PanelPopup" style="display:block;width:500px;height:400px"  ScrollBars="Vertical">

<table>
<tr>
<td align="left" colspan="2" class="style1" style="height: 30px">
    <asp:Label ID="Label15" runat="server" Text="More Items"></asp:Label>
      <tr>
        <td align="left" colspan="5" valign="top" style="height: 6px">
         <img src="images/top_line_bg.jpg" style="height: 2px; width: 288px"> </img>
        </td>
       </tr>

</td>
</tr>
</table>
<table >
    <tr>
        <td class="popuplbltdwithpadding">

        </td>
        <td>
      </td>
    </tr>
    <tr>
    <td>
    <table>
    <tr>
    <td>
        <asp:GridView ID="grdparameter" runat="server" CellPadding="5"
            CssClass="CustomGrid" ShowFooter="True"
        AutoGenerateColumns="False" GridLines="Horizontal" AllowPaging="True"
            DataKeyNames="ParameterId" Width="249px"
        onselectedindexchanged="grdparameter_SelectedIndexChanged1"
        onpageindexchanging="grdparameter_PageIndexChanging" Height="16px"
            style="margin-right: 0px">
        <Columns>
        <asp:TemplateField>
        <ItemStyle CssClass="w" />
            <HeaderTemplate>
              <input id="chkAll" type="checkbox" onclick="javascript:SelectAllCheckboxes(this);" runat="server"/>
              <asp:Label ID="lblSelectAll" runat="server" Text="Select All" CssClass="grdheaderstyle"></asp:Label>
            </HeaderTemplate>
        <ItemTemplate>
            <asp:CheckBox ID="chkSelect" AutoPostBack="false" runat="server" />
        </ItemTemplate>
        </asp:TemplateField>
        <asp:BoundField DataField="ParameterName" HeaderText="Scheduled Items"
                                    ReadOnly="True" />
        </Columns>
        </asp:GridView>
        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
            CssClass="MiniInnerpageGrid" GridLines="Horizontal">
            <Columns>
                <asp:TemplateField>
                    <ItemTemplate>
                        <asp:ImageButton ID="Imageadd" runat="server" AlternateText="<%#Bind('ID')%>"
                            CssClass="icon" ImageUrl="~/images/HMS Buttons/icon1.jpg"
                            OnClick="Imageadd_Click" ToolTip="Copy" />
                    </ItemTemplate>
                    <ItemStyle CssClass="w" />
                </asp:TemplateField>
                <asp:BoundField DataField="Type" HeaderText="Type" />
                <asp:BoundField DataField="Medicine_Name" HeaderText="Medicine Name" />
                <asp:BoundField DataField="Dosage" HeaderText="Dosage" />
                <asp:BoundField DataField="No_Days" HeaderText="No Of Days" />
                <asp:BoundField DataField="DOV" HeaderText="DOV" />
            </Columns>
            <FooterStyle CssClass="GridFooter" />
            <HeaderStyle CssClass="grdheaderstyle" />
            <PagerStyle CssClass="GridFooter" />
            <RowStyle CssClass="grdrowstyle" />
        </asp:GridView>
    </td>
    </tr>
    </table>
    </td>
    </tr>
    </table>
     <table >
    <tr>
      <td class="popuplbltdwithpadding">
          <asp:ImageButton ID="btnsaveparameter"
              ImageUrl="~/images/HMS Buttons/SaveHMS.jpg" runat="server" onclick="btnsaveparameter_Click"
               />
          </td>
       <td  class="popuplbltdwithpadding">
           <asp:ImageButton ID="ImageButton1" runat="server"
               ImageUrl="~/images/HMS Buttons/Close.jpg"/>
       </td>
      </tr>
    </table>
    <table>
</table>
</asp:Panel>
    <asp:Button ID="Button2" runat="server" Text="Button" style="display:none" />
    <asp:ModalPopupExtender ID="ModalPopup_Items" runat="server" TargetControlID="Button2" OnOkScript="btnsaveparameter_Click(object sender, ImageClickEventArgs e)" CancelControlID="ImageButton1" OkControlID="btnsaveparameter"
     ViewStateMode="Enabled" Drag="True" BackgroundCssClass="modalBackground"
    PopupControlID="Panel1" Enabled="True" DropShadow="True" DynamicServicePath="">
    </asp:ModalPopupExtender>

protected void btnsaveparameter_Click(object sender, ImageClickEventArgs e)
       {
           //ImageButton b = (ImageButton)sender;
           //GridViewRow row = (GridViewRow)sender;
           //int rowIndex = row.RowIndex;
           foreach (GridViewRow row in GridView1.Rows)
           {
               CheckBox chk = (CheckBox)row.FindControl("chkSelect");
               if (chk.Checked)
               {
                   string ParameterId = grdcareplan.DataKeys[0].Value.ToString();
                   MySqlConnection StrConnection = null;
                   MySqlCommand StrCommand = null;

                   try
                   {
                       StrConnection = new MySqlConnection();
                       StrConnection.ConnectionString = StrConn;
                       StrConnection.Open();

                       StrCommand = new MySqlCommand();
                       StrCommand.CommandType = CommandType.StoredProcedure;
                       StrCommand.CommandText = "Insert_Parameter_Name";
                       StrCommand.Connection = StrConnection;


                       //StrCommand.Parameters.AddWithValue("_ParameterName", dropdowndisease.SelectedItem.Text);
                       StrCommand.Parameters.AddWithValue("_DiseaseId", Convert.ToInt32(ViewState["DiseaseId"]));
                       StrCommand.Parameters.AddWithValue("_ParameterId", ParameterId);
                       StrCommand.Parameters.AddWithValue("_Branch_Id", Convert.ToInt32(Session["Branchid"]));
                       StrCommand.Parameters.AddWithValue("_Tenant_Id", Convert.ToInt32(Session["Tenantid"]));
                       StrCommand.Parameters.AddWithValue("_Patient_Id", Convert.ToInt32(Session["DiagnosisClickId"]));


                       //  StrCommand.Parameters.AddWithValue("_Submit_Date", DateTime.Now);

                       StrCommand.ExecuteNonQuery();
                       BindCarePlan();
                       ModalPopupExtender1.Show();
                       Biomade.Visible = true;
                   }

                   catch (Exception ex)
                   {
                       obj.InfoEntry(DateTime.Now + "     " + "BtnSave1_Click" + "     " + "AccountBalance.aspx" + "     " + ex.Message, "");
                       obj.InfoEntry(DateTime.Now + "     " + ex.StackTrace, "");
                       Session["strerrormsg"] = DateTime.Now + "     " + "BtnSave1_Click" + "     " + "AccountBalance.aspx" + "     " + ex.Message;
                       Session["strerrortrace"] = DateTime.Now + "     " + ex.StackTrace;
                       Response.Redirect("ErrorPage.aspx");
                   }
                   finally
                   {
                       StrConnection.Close();
                       StrConnection.Dispose();
                   }
               }
           }
       }
  }