Problem in custom section,  i am just started to create custom section based  on "http://www.geckonewmedia.com/blog/2009/8/3/how-to-create-a-custom-section-in-umbraco-4" article. but now i get little problem.
If you click on other section "click on content" and come back to custom section. it will append all text (see screen bellow)  if we refresh page that it works again ( see image second bellow).
how to solve that problem?

  public override void Render(ref XmlTree Tree)
        {
           var DocType = XmlTreeNode.Create(this);
           
            DocType.Icon = "docPic.gif";
            DocType.Action = "javascript:openDocType()"; DocType.Text = "Docuement Type";
          // Add the node to the tree
          Tree.Add(DocType);

             var Template = XmlTreeNode.Create(this);
            Template.Text = "Template";
            Template.Icon = "docPic.gif";
            Template.Action = "javascript:openTemplate()";
          // Add the node to the tree
          Tree.Add(Template);

          var Content = XmlTreeNode.Create(this);
          Content.Text = "Content";
          Content.Icon = "docPic.gif";
          Content.Action = "javascript:openContent()";
          // Add the node to the tree
          Tree.Add(Content);


        }

public override void RenderJS(ref StringBuilder Javascript)
            {


                Javascript.Append(@"
              function openDocType() {
                      parent.right.document.location.href = 'deployment/DDocType.aspx';     }
             ");

                Javascript.Append(@"
            function openTemplate() {
                  parent.right.document.location.href = 'deployment/DTemplate.aspx';
                }
           ");

                Javascript.Append(@"
            function openContent() {
                  parent.right.document.location.href = 'deployment/DContent.aspx';
                }
           ");
       }

image first

Image second . after refresh page.

Thanks.