>I don't understand the problem, Michel. If the Common class is in the same namespace as your Web Service methods, then you shouldn't have to do anything. If it's not, then you simply have to have an Imports statement that references it. Is this not working for you?

In reality DoCommonProcess() returns a boolean so the proper call I have to do on all the methods that require it would be:

    Public Shared Function GetMessage(ByVal tdDate As Date, ByVal tnForum As Integer) As String
    If Not DoCommonProcess() Then
       Throw New System.Exception("My message here")
    End If
    Return ""
    End Function

    Public Shared Function GetCategory(ByVal tdDate As Date, ByVal tnForum As Integer) As String
    If Not DoCommonProcess() Then
       Throw New System.Exception("My message here")
    End If
    Return ""
    End Function

So, I don't want to repeat the same code for all the methods that need it. That is why I am looking at how I can have GetMessage() and GetCategory() to inherits of that Common.DoCommonProcess() method so I don't have to write the same code over and over again.