I have a Default.asmx file that contains only this line:

<%@ WebService Language="vb" Codebehind="WebService.vb"
class="MyProgramBS.WebService" %>

All my WEbMethods are in MyProgramBS.WebService: e.g.
<WebMethod()> Public Function CanPayOnline(ByVal loginID As Long) as
Boolean()

When I test this, the default value of the namspace is
http://tempuri.org/

I tried modifying the code in Default.asmx as:
Imports System.Web.Services

<System.Web.Services.WebService(Namespace:="http://www.MyWebSite.net/WebService")>
_
Public Class WebService
   Inherits System.Web.Services.WebService

   ' WEB SERVICE EXAMPLE
   ' The HelloWorld() example service returns the string Hello World.
   ' To build, uncomment the following lines then save and build the
project.
   ' To test this web service, ensure that the .asmx file is the
start page
   ' and press F5.
   '
   '<WebMethod()> _
   'Public Function HelloWorld() As String
   '   Return "Hello World"
   'End Function

End Class

but nothing happens. I think it is because I do not write any of my
web methods in the asmx file, but I redirect to WebService.vb . So how
can I change the Namespace this way?