Calender extender extended with textbox control not popping up

Question

Hi all,

Calender extender extended with textbox control not popping up when i click on the textbox.. I want that the calender should pop up when a user clicks on the textbox... I have attached the code plzz let me know where is the mistake.. I am using VS 2005 with ajax..

<table width="100%" border="0" cellspacing="1" cellpadding="1" style="font-family: 'Times New Roman'">
  <tr>
    <td> <table width="500" border="0" cellspacing="2" cellpadding="2">
        <tr>
          <td colspan="2" style="text-align: left">
              <strong><span style="font-size:large">Project Details</span> </strong></td>
        </tr>
        <tr>
            <td colspan="2" style="color: #ff3333; text-align: left">
                * Fields are mandatory</td>
        </tr>
        <tr>
          <td align="left" style="width: 104px">Project Name:<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server"
                  ErrorMessage="*" ControlToValidate="txtprojname"></asp:RequiredFieldValidator></td>
          <td align="left">&nbsp;<asp:TextBox ID="txtprojname" runat="server"></asp:TextBox></td>
        </tr>
        <tr>
          <td align="left" style="width: 104px">Description:<asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server"
                  ErrorMessage="*" ControlToValidate="txtprojdescription"></asp:RequiredFieldValidator></td>
          <td align="left">&nbsp;<asp:TextBox ID="txtprojdescription" runat="server" TextMode="MultiLine"></asp:TextBox></td>
        </tr>
        <tr>
          <td align="left" style="width: 104px">Start Date:<asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server"
                  ErrorMessage="*" ControlToValidate="txtstartdate"></asp:RequiredFieldValidator></td>
          <td align="left">&nbsp;<asp:TextBox ID="txtstartdate" runat="server"></asp:TextBox>&nbsp;
              <cc1:CalendarExtender ID="CalendarExtender1" PopupButtonID="txtstartdate" Format="MMMM d, yyyy" TargetControlID="txtstartdate" runat="server">
              </cc1:CalendarExtender>
          </td>
        </tr>
        <tr>
          <td align="left" style="width: 104px">Team Size:<asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server"
                  ErrorMessage="*" ControlToValidate="drpteamsize"></asp:RequiredFieldValidator></td>
          <td align="left">&nbsp;<asp:DropDownList ID="drpteamsize" runat="server" AutoPostBack="True">
                  <asp:ListItem Value="0">1</asp:ListItem>
                  <asp:ListItem Value="1">2</asp:ListItem>
                  <asp:ListItem Value="2">3</asp:ListItem>
                  <asp:ListItem Value="3">4</asp:ListItem>
                  <asp:ListItem Value="4">5</asp:ListItem>
                  <asp:ListItem Value="5">6</asp:ListItem>
                  <asp:ListItem Value="6">7</asp:ListItem>
                  <asp:ListItem Value="7">8</asp:ListItem>
                  <asp:ListItem Value="8">9</asp:ListItem>
                  <asp:ListItem Value="9">10</asp:ListItem>
              </asp:DropDownList></td>
        </tr>
        <tr>
          <td align="left" style="width: 104px">End Date:<asp:RequiredFieldValidator ID="RequiredFieldValidator5" runat="server"
                  ErrorMessage="*" ControlToValidate="txtenddate"></asp:RequiredFieldValidator></td>
          <td align="left">&nbsp;<asp:TextBox ID="txtenddate" runat="server"></asp:TextBox>&nbsp;
              <cc1:CalendarExtender ID="CalendarExtender2" Format="MMMM d, yyyy" PopupButtonID="txtenddate" TargetControlID="txtenddate" runat="server">
              </cc1:CalendarExtender>
          </td>
        </tr>
        <tr>
          <td align="left" style="width: 104px">Duration:<asp:RequiredFieldValidator ID="RequiredFieldValidator6" runat="server"
                  ErrorMessage="*" ControlToValidate="txtduration"></asp:RequiredFieldValidator></td>
          <td align="left">&nbsp;<asp:TextBox ID="txtduration" runat="server" ReadOnly="True"></asp:TextBox></td>
        </tr>
        <tr>
          <td colspan="2" align="left" style="height: 28px">&nbsp;<asp:Button ID="btnaddproj" runat="server" Text="Add Project Details" OnClick="btnaddproj_Click" /></td>
        </tr>
      </table></td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td colspan="2">&nbsp;<asp:GridView ID="gvProjectDetails" runat="server" AllowPaging="True" AutoGenerateColumns="False"
            BackColor="White" BorderColor="#CCCCCC" BorderStyle="None" BorderWidth="1px"
            CellPadding="3" Font-Names="Times New Roman" Width="100%" OnSelectedIndexChanged="gvProjectDetails_SelectedIndexChanged">
            <RowStyle ForeColor="#000066" />
            <Columns>
                <asp:BoundField DataField="ProjectID" HeaderText="Project ID" />
                <asp:BoundField DataField="ProjectName" HeaderText="Project Name" />
                <asp:BoundField DataField="Description" HeaderText="Description" />
                <asp:BoundField DataField="StartDate" HeaderText="Start Date" />
                <asp:BoundField DataField="EndDate" HeaderText="End Date" />
                <asp:BoundField DataField="Duration" HeaderText="Duration" />
                <asp:BoundField DataField="TeamSize" HeaderText="Team Size" />
                <asp:CommandField SelectText="Select" ShowSelectButton="true" />
            </Columns>
            <FooterStyle BackColor="White" ForeColor="#000066" />
            <PagerStyle BackColor="White" ForeColor="#000066" HorizontalAlign="Left" />
            <SelectedRowStyle BackColor="#669999" Font-Bold="True" ForeColor="White" />
            <HeaderStyle BackColor="#006699" Font-Bold="True" ForeColor="White" />
            <AlternatingRowStyle BackColor="LightGoldenrodYellow" Font-Names="Times New Roman"
                Font-Size="0.85em" />
        </asp:GridView>
    </td>
  </tr>
</table>