C# Code

  protected void Page_Load(object sender, EventArgs e)
    {
        // Connect the chart to the data source
        // In this example we are holding a table in memory
        DragDropChart.DataSource = Data;

        // Hook up the Drag Drop event handler.  This could be done in the ASPX file.
        DragDropChart.ItemDropped += new OrgChart.Core.OrganisationChartDragDropEventHandler(DragDropChart_ItemDropped);
    }

    /// <summary>
    /// This method is called once an item is dragged and dropped onto another item!
    /// </summary>
    /// <param name="sender">The Org Chart</param>
    /// <param name="DraggedItemId">The ItemId of the dragged item</param>
    /// <param name="DroppedItemId">The ItemId of dropped item</param>
    bool DragDropChart_ItemDropped(object sender, string DraggedItemId, string DroppedItemId)
    {
        // Don't let the user change the first ( root item ) 
        if (DraggedItemId == "1")
        {
            // Returning false "Cancels" the drop event
            return false;
        }

        // Update the data source
        UpdateRow(DraggedItemId, DroppedItemId);
        return true;
    }

Html Markup

<cc1:DataBoundOrganisationChart ID="DragDropChart" runat="server">
                <DragDrop Enabled="true" />                
</cc1:DataBoundOrganisationChart>