How to convert a datareader to datatable

I have a question about converting a datareader to a datatable. In my code, I have a datareader created in one class and passed to another class that I want to convert it to a datatable.

When I do this, it does not seem to work, as the table remains empty. If I do the conversion in the same function, it works fine.

Its only when I pass the datareader to another function that it stops working. Is this because the dr is closed or something? How do I overcome this problem? Any help would be great.

Check this out:

Public Function ExecuteQuery(ByVal s As String, ByVal condb As SqlConnection, ByVal ParamArray params() As SqlParameter) As DataTable
        Dim dt As DataTable = Nothing
        Using da As New System.Data.SqlClient.SqlDataAdapter(s, condb)               
            dt = New DataTable
            If params.Length > 0 Then
                da.SelectCommand.Parameters.AddRange(params)
            End If
            If da.SelectCommand.Connection.State <> ConnectionState.Open Then da.SelectCommand.Connection.Open()
            da.Fill(dt)                    
        End Using
        Return dt
End Function