How to merge two datatables in ASP.NET

Another post, just because of the continuous query in forums. Past one week I saw 3 candidate asking the same question so I thought I will share this code.

private static DataTable MergeDT(DataTable Dt1, DataTable Dt2)
{
  if (Dt1 != null && Dt1.Rows.Count > 0)
  {
    DataRow dr;
 
    for (int i = 0; i < Dt2.Columns.Count; i++)
    {
      Dt1.Columns.Add(new DataColumn(Dt2.Columns[i].ColumnName));
 
      if (Dt2.Rows.Count > 0)
        for (int j = 0; j < Dt2.Rows.Count; j++)
        {
          dr = Dt1.Rows[j];
          dr[Dt1.Columns.Count - 1] = Dt2.Rows[j][i];
          dr = null;
        }
    }
  }
 
  return Dt1;
}