Scrollpane Not Working

Question

I am trying to have a JFrame with multiple panels, one of which will allow scrolling. I assign a scrollpane to a JPanel, which will contain multiple (dynamically changing) Labels. When the number of Labels exceeds the size that the JPanel is allocated (which is the reason the scrollpane is needed in the firstplace), the scrollable feature kicks in (which is good), but the entire list of labels appears, exceeding the region allocated to the JPanel and appearing over the panels below this one. How do I correct this? Thanks!
import javax.swing.*;
import java.awt.*;
class TestScrollPane
     public static void main(String[] args)
          JFrame jf = new JFrame("Test Frame");
          jf.setLayout(new GridLayout(2,2));
          jf.setSize(400,500);
jf.add(new Label("Top Left Panel"));
JPanel jp1 = new JPanel(new BorderLayout());
          jp1.add("North", new Label("On top"));
          JPanel jp = new JPanel(new GridLayout(20,1));
          for(int i=0; i<20; i++)
               Label l = new Label(i+ "th Label");
               l.setBackground(Color.WHITE);
               jp.add(l);
          JScrollPane scrollPane = new JScrollPane(jp);
          scrollPane.setPreferredSize(new Dimension(50, 50));
          jp1.add("Center", scrollPane);
          jf.add(jp1);
          jf.add(new Label("Bottom Left Panel"));
          jf.add(new Label("Bottom Right Panel"));
          jf.setVisible(true);
}

Answer 1

Your problem is one of the unexpected results that come from mixing AWT and Swing visual components. My answer: don't do this -- change all of your "Labels" to "JLabels".