ASP.net login label change

Question

I got a problem edit a login..

I want to remove the labels from my login but comes up with an error : Server Error in '/' Application."

Here is the code :

<table id="TableData" cellpadding="5">
            <tr>
               <td><tr>
                    <br />
                    <asp:Label ID="LabelFirstName" runat="server"></asp:Label>
                    <br />
                    <asp:TextBox ID="TextBoxFirstName" runat="server"></asp:TextBox>
                </td></tr>
                <td><tr>
                    <br />
                    <asp:Label ID="LabelLastName" runat="server"></asp:Label>
                    <br />
                    <asp:TextBox ID="TextBoxLastName" runat="server"></asp:TextBox>
                </td></tr>
                <td>
                    <br /><tr>
                    <asp:Label ID="LabelEMail" runat="server"></asp:Label>
                    <br />
                    <asp:TextBox ID="TextBoxEMail" runat="server"></asp:TextBox>
                </td>
            </tr>
            <tr>
                <td colspan="2">
                    <br />
                    <asp:Label ID="LabelSeqQuestion" runat="server"></asp:Label>
                    <br />
                    <asp:DropDownList ID="DropDownListSeqQuestions" runat="server">
                    </asp:DropDownList>
                </td>
                <td>
                    <br />
                    <asp:Label ID="LabelSeqAnswer" runat="server"></asp:Label>
                    <br />
                    <asp:TextBox ID="TextBoxSeqAnswer" runat="server"></asp:TextBox>
                </td>
            </tr>
            <tr>
                <td colspan="3">
                <br />
                <asp:Label ID="LabelOptFields" runat="server"></asp:Label>
           </td>
            </tr>
        </table>

I cant get it to work anyhow

The reported error was:

[NullReferenceException: Object reference not set to an instance of an object.] UpdateProfile.LocalizePage() +681 UpdateProfile.Page_Load(Object sender, EventArgs e) +514 System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +24 System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +41 System.Web.UI.Control.OnLoad(EventArgs e) +131 System.Web.UI.Control.LoadRecursive() +65 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2427

When I remove <asp:Label ID="LabelFirstName" runat="server"></asp:Label>.