ASP.NET Mobile RegularExpressionValidator Control

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

<script runat="server">
sub page2(Sender as Object,E as EventArgs)
if Page.IsValid then
  ActiveForm=f2
  lbl2.Text="The ZIP code entered is: " & txt1.text
end if
end sub
</script>

<Mobile:Form id="f1" runat="server">
  <Mobile:Label runat="server">
  Please enter a ZIP code
  </Mobile:Label>

  <Mobile:TextBox id="txt1" runat="server"/>

  <Mobile:RegularExpressionValidator
  ControlToValidate="txt1"
  ValidationExpression="\d{5}"
  Text="The zip code must be five digits!"
  runat="server" />

  <Mobile:RequiredFieldValidator
  ControlToValidate="txt1"
  Text="A ZIP code is required!"
  runat="server" />

  <Mobile:Command runat="server"
  OnClick="page2">Submit
  </Mobile:Command>
</Mobile:Form>

<Mobile:Form id="f2" runat="server">
  <Mobile:Label id="lbl2" runat="server" />
</Mobile:Form>