Mobile Control ASP.Net

<%@ Page 
    Inherits="System.Web.UI.MobileControls.MobilePage" 
    Language="VB" 
%>
<%@ Register 
    TagPrefix="mobile" 
    Namespace="System.Web.UI.MobileControls" 
    Assembly="System.Web.Mobile" 
%>

Sub OK_OnSubmit(Sender As Object, E As EventArgs)
    If cvCheckDate.IsValid Then
        ActiveForm = FinishForm
        lbl2.Text = "You entered " & txtDate.Text
    End If
End Sub

    id="StartForm" 
    runat="server">
            runat="server" 
        id="lbl1"
        Text="Please enter a date:" 
    />
            runat="server" 
        id="txtDate"
    />
            id="cvCheckDate" 
        controltovalidate="txtDate"
        operator="DataTypeCheck" 
        type="Date" 
        errormessage="You must enter a date!!!"
        runat="server"
    />
            runat="server" 
        id="cmdOK"
        OnClick="OK_OnSubmit" 
        Text="OK" 
    />

    id="FinishForm" 
    runat="server">
            runat="server" 
        id="lbl2"
    />