-----------------------------------------------------------------------------
    <summary>
    Transforma un xml en otro xml
    </summary>
    <param name="txt">un string que contiene el xml origen</param>
    <param name="xslFile">Archivo xsl para la transformacion</param>
    <returns>el xml transformado</returns>
    -----------------------------------------------------------------------------
   Private Function xslTrans(ByVal txt As String, ByVal xslFile As String) As XmlDocument
       Dim xslTran As New XslTransform
       Dim oDocOut As New XmlDocument
       Dim oDoc As New XmlDocument
       Dim oNav As XPath.XPathNavigator
       Dim oXsl As XmlTextReader
       Try
           oXsl = New XmlTextReader(xslFile)
           oDoc.LoadXml(txt)
           oNav = oDoc.CreateNavigator()
           xslTran.Load(oXsl, Nothing, Me.GetType().Assembly.Evidence)
           oDocOut.Load(xslTran.Transform(oNav, Nothing, New Xml.XmlUrlResolver))
       Catch ex As Exception
           Console.Write("Error:" + vbCr + ex.Message)
       End Try
       oDocOut.Normalize()
       Return oDocOut
   End Function