code: @Override
      protected String defaultActionHtmlStart() {
  
          StringBuffer result = new StringBuffer(2048);
          result.append(htmlStart(null));
          result.append(getList().listJs());
          result.append(CmsListExplorerColumn.getExplorerStyleDef());
          result.append("<script language='JavaScript'>\n");
          result.append(new CmsExplorer(getJsp()).getInitializationHeader());
          result.append("\ntop.updateWindowStore();\n");
          result.append("top.displayHead(top.win.head, 0, 1);\n}\n");
          result.append("</script>");
          result.append(bodyStart("dialog", "onload='initialize();'"));
          result.append(dialogStart());
          result.append(dialogContentStart(getParamTitle()));
          return result.toString();
      }
docs: Generates the dialog starting html code.<p>
  
  @return html code