Union two diffrent Datatable In vb.net

Public Function mergeDTs(ByVal dt1 As DataTable, ByVal dt2 As DataTable) As DataTable
'dt1.Columns.Add("ContactID")
Dim dtResult As DataTable = dt1.Clone()
Dim ds As New DataSet

For Each dr As DataRow In dt1.Rows
dtResult.Rows.Add(dr.ItemArray)
Next
For Each dr As DataRow In dt2.Rows

dtResult.Rows.Add(dr.ItemArray)

'dtResult.Columns.Add("ContactID")

Next
Dim dtFinalResult As New DataTable

Return dtResult
End Function