title: JScrollPane layout
body: <p>I want to add table2 into the scrollpanel (called feedback) which already has table1 in there. But only one table shows up. If I use feedback.add(table2), only the 1st table shows (I guess the 2nd table is behind the first one, but I don't know how to make the second one below the first one). if I use feedback.getViewport().add(table2, null), only the 2nd table shows. Do I need to use some layout manager here? i tried to search online about scrollpanel layout but didn't get any solutions. Could anyone tell me what's the problem or give me some related example links? Thanks a lot. The relative code are:</p>
  
  <pre><code>        content = getContentPane();
          content.setLayout(new FlowLayout());
          scrollPane = new JScrollPane(tree);
          feedback = new JScrollPane(table1);
          JSplitPane splitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT,scrollPane, feedback);
          content.add(splitPane);
              .
              .
              .
              .
          feedback.add(table2);
          //i add this, but still doesn't work 
          content.add(table2);
  </code></pre>