Visual Basic

<Orders>
<OrderHeader>
  <CustomerPoNumber>TEST1</CustomerPoNumber> 
  <ErrorMessages>
      <ErrorDescription>Invalid   Po 'TEST1'</ErrorDescription>
  </ErrorMessages>
</OrderHeader>
<OrderDetails>
  <Stock>
 <Line>0001</Line>
  <ErrorMessages>
      <ErrorDescription>'EAE' invalid</ErrorDescription>
      <ErrorDescription>'EAS' invalid</ErrorDescription>
  </ErrorMessages>
  </Stock>
  <Stock>
 <Line>0002</Line>
   <ErrorMessages>
      <ErrorDescription>Price invalid</ErrorDescription>
   </ErrorMessages>
  </Stock>
</OrderDetails>
</Orders>

Private Function GetErrors(ByVal XML As String, ByVal Path As String) As DataTable
    Try
        Dim DOC As New Xml.XmlDocument
        DOC.LoadXml(XML)

        Dim ndParent As XmlNodeList
       'Path = //Orders
        ndParent = DOC.SelectNodes(Path)

        Dim nd As XmlNode
        Dim ndC1 As XmlNode
        Dim ndC2 As XmlNodeList
        Dim nd1 As XmlNode
        Dim nd2 As XmlNode
        Dim out As String = ""


        Dim dt As New DataTable
        dt.Columns.Add("PoNum")
        dt.Columns.Add("So")
        dt.Columns.Add("Line")
        dt.Columns.Add("Error")
        dt.Columns.Add("ErrHdr")
        Dim row As DataRow

        Dim PoNum As String = ""
        Dim Line As Integer = 0
        Dim errmsg As String = ""
        Dim errhdr As String = ""

        For Each nd In ndParent
            'below reads the first level i.e. order header + order details
            For Each ndC1 In nd.ChildNodes
                Select Case ndC1.Name.Trim
                    Case "OrderHeader"
                       'get the childnodes of OrderHeader
                       'xml result should search for FieldName i.e. "CustomerPoNumber"
                        ndC2 = ndC1.ChildNodes
                        PoNum = XmlResult(ndC2, "CustomerPoNumber")
                        errhdr = XmlResult(ndC2, "ErrorMessages")
                        'out &= XmlResult(ndC2, "ErrorMessages")

                    Case "OrderDetails"
                        'ndC2 = ndC1.ChildNodes
                        For Each nd1 In ndC1
                            Line = Me.XmlResult(nd1.ChildNodes, "Line")
                            For Each nd2 In nd1.ChildNodes 'stockline
                                If nd2.Name = "ErrorMessages" Then
                                    errmsg = Me.XmlResult(nd2.ChildNodes, "ErrorDescription") & " ; "
                                   ' out &= Me.XmlResult(nd2.ChildNodes, "ErrorDescription")
                                End If
                                Application.DoEvents()
                            Next
                            row = dt.NewRow
                            row("PoNum") = PoNum
                            row("Line") = Line
                            row("Error") = errmsg
                            row("ErrHdr") = errhdr
                            dt.Rows.Add(row)
                            Application.DoEvents()
                        Next
                End Select
            Next
          Next

        Return dt

    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
End Function
Public Function XmlResult(ByVal node As XmlNodeList, ByVal Column As String) As String
    Try
        Dim nd As XmlNode
        Dim nd2 As XmlNode
        Dim strOut As String = ""

        For Each nd In node
            If nd.Name = Column Then
                For Each nd2 In nd.ChildNodes
                    strOut = strOut & nd2.InnerText & vbCrLf
                    Application.DoEvents()
                Next
            End If
        Next

        nd = Nothing
        Return strOut
    Catch ex As Exception
        MsgBox(ex.Message, MsgBoxStyle.Exclamation)
    End Try
End Function

Public Function XmlToDataTable(ByVal path As String) As DataTable
        Dim dt As New DataTable
        Dim doc As New XmlDocument()
        Dim PoNum As String = String.Empty
        Dim Header As String = String.Empty
        doc.Load(path)
        dt.Columns.Add("PoNum")
        dt.Columns.Add("Header")
        dt.Columns.Add("Line")
        dt.Columns.Add("Error")
        Dim cnt As Integer = doc.SelectNodes("Orders/OrderHeader").Count
        For k As Integer = 0 To cnt - 1  
            Dim node As XmlNode = doc.SelectNodes("Orders/OrderHeader").Item(k)
            PoNum = node.Item("CustomerPoNumber").InnerText
            Header = node.Item("ErrorMessages").InnerText
            Dim n As Integer = doc.SelectNodes("Orders/OrderDetails").Count
            For m As Integer = 0 To n - 1
                Dim element As XmlNode = doc.SelectNodes("Orders/OrderDetails").Item(m)
                Dim obj(3) As Object
                obj(0) = PoNum : obj(1) = Header
                For Each stocks As XmlNode In element.ChildNodes
                    Dim line As String = stocks.Item("Line").InnerText
                    Dim description As String = stocks.Item("ErrorMessages").InnerXml.Replace("</ErrorDescription><ErrorDescription>", " & ").Replace("<ErrorDescription>", "").Replace("</ErrorDescription>", "")
                    obj(2) = line : obj(3) = description
                    dt.Rows.Add(obj)
                Next
            Next
        Next
        Return dt
    End Function

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim newThread As New Threading.Thread(New Threading.ThreadStart(AddressOf ChangeBGColour))
        newThread.Start()
        Label1.BackColor = Color.Red

    End Sub

    Delegate Sub changeLabelColour()

    Private Sub ChangeBGColour()

        Threading.Thread.Sleep(3000)
        If Me.Label1.InvokeRequired Then
            Dim c As New changeLabelColour(AddressOf ChangeBGColour)
            Me.Invoke(c)
        Else
            Label1.BackColor = Color.Yellow
        End If

    End Sub