code: public void setContent(Widget content) {
  
          if (m_content != null) {
              m_content.removeFromParent();
          }
          if (m_isFrame) {
              m_contentPanel.setWidget(content);
          } else {
              m_popup.setMainContent(content);
          }
          m_content = content;
      }
docs: Sets the content widget.<p>
  
  @param content the content widget