title: Appending in an existing xml file using dataset
body: <p>I made this code but it has a problem that everytime i run it ..it overwrites my xml file and nothing new is added 
  this is my xml file:</p>
  
  <pre><code>- &lt;DATA&gt;
  - &lt;Users&gt;
    &lt;MonopolyID&gt;User2&lt;/MonopolyID&gt; 
    &lt;Password&gt;pass2&lt;/Password&gt; 
    &lt;FirstName&gt;User2Name&lt;/FirstName&gt; 
    &lt;LastName&gt;User2LastName&lt;/LastName&gt; 
    &lt;/Users&gt;
    &lt;/DATA&gt;
  </code></pre>
  
  <p>u can see that user1 was overwritten
  anyway this is my code:</p>
  
  <pre><code>public partial class SignUpPage : Form
      {
  private void button1_Click(object sender, EventArgs e)
          {
              DataSet ds = new DataSet();
              DataTable dt = new DataTable();
              DataColumn dc = new DataColumn("MonopolyID", typeof(string));
              dt.Columns.Add(dc);
              dc = new DataColumn("Password", typeof(string));
              dt.Columns.Add(dc);
              dc = new DataColumn("FirstName", typeof(string));
              dt.Columns.Add(dc);
              dc = new DataColumn("LastName", typeof(string));
              dt.Columns.Add(dc);
              DataRow dr = dt.NewRow();
              dt.Rows.Add(textBox3.Text, textBox4.Text, textBox1.Text, textBox2.Text);//here just putting  the texts in the texts box for the first row
              dt.TableName = "Users";
              ds.Tables.Add(dt);
              ds.DataSetName = "DATA";
              ds.WriteXml(@"pathOfTheFile..");
      }
  }
  </code></pre>