title: Weird thing happening in DataTable: Creating a backup DataTable
body: <pre><code>        DataTable dt1 = new DataTable(); //I made this as a backup
          //add 3 columns
          dt1.Columns.Add();
          dt1.Columns.Add();
          dt1.Columns.Add();
          MessageBox.Show("Number of Columns in dt1: " + dt1.Columns.Count);
          DataTable dt2 = dt1;
          //I added another column just to say that that table changed
          dt2.Columns.Add();
          MessageBox.Show("Number of Columns in dt1: " + dt1.Columns.Count + "\r\nNumber of Columns in dt2: " + dt2.Columns.Count);
          //there's four columns now in both tables even though I added the column only in dt2
  </code></pre>
  
  <p>Why is this happening? And how do I change it so that the dt1 is not changed no matter what I do to dt2?</p>