circular reference in self-nested table 'firstname1'. asp.net
<p>This is the error i am getting "circular reference in self-nested table 'firstname1'".</p>

<p>I want to Hierarchical Data binding. Employee and their supervisor are in the same table.</p>

<p>I am taking reference from <a href="http://weblogs.asp.net/alessandro/archive/2008/03/01/part-2-building-and-binding-hierarchical-data-from-the-database-to-the-asp-net-navigation-controls.aspx" rel="nofollow">http://weblogs.asp.net/alessandro/archive/2008/03/01/part-2-building-and-binding-hierarchical-data-from-the-database-to-the-asp-net-navigation-controls.aspx</a>.</p>

<p>But it is giving error on generating Xml.</p>

<pre><code>using (SqlConnection con = new SqlConnection(WebConfigurationManager.ConnectionStrings["RMSConnection"].ToString()))
{
    string SqlCommand = "SELECT EmployeeId,FirstName,ReportToId FROM tblEmployee";
    SqlDataAdapter adapter = new SqlDataAdapter();
    adapter.SelectCommand = new SqlCommand(
    SqlCommand, con);
    adapter.Fill(ds);
    ds.Tables[0].TableName = "FirstName1";
    DataRelation dr = new DataRelation("pageId_parentId",ds.Tables["FirstName1"].Columns["EmployeeId"], ds.Tables["FirstName1"].Columns["ReportToId"]);
    dr.Nested = true;

    ds.Relations.Add(dr);
} 
//string s= ds.GetXml();    
</code></pre>

<p>above is my code.
Please Suggest.</p>

<p><img src="http://i.stack.imgur.com/oSRHI.png" alt="enter image description here"></p>
