Exception in thread "main" java.lang.noClassDefFoundError org/jdom/input/SAXBuilder
<p>Hello this is Lonnie Ribordy,</p>

<p>I have a program i am trying to write and part of it uses a 3rd party api called JDom, 
when i compile my program the it compiles perfectly fine.. but, when i try to run it i get the Exception in thread "main" java.lang.noClassDefFoundError org/jdom/input/SAXBuilder</p>

<p>my program is as below...</p>

<pre><code>
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.util.*;
import org.jdom.*;
import org.jdom.input.*;
import org.jdom.output.*;

public class COS extends JPanel implements ActionListener{
    static JFrame f=new JFrame();
    Image bgImage=null;
    String message="";
    public COS(){
     try{
      String xml="background.xml";
      SAXBuilder builder=new SAXBuilder();
      Document doc=builder.build(new File(xml));
      Element root=null;
      Element img=null;
      String fimg=null;
      try{
       root=doc.getRootElement();
       img=root.getChild("bgimage");
       fimg=img.getText();
      } catch(Exception e){
      }
      getFileImage(fimg);
     } catch(Exception e){
      message="File load failed: "+e.getMessage();
     }
    }
    public void paintComponent(Graphics g){
     if(bgImage!=null){
      g.drawImage(bgImage,0,0,this);
     }
     else{
      g.drawString(message,40,40);
     }
    }
    public void getFileImage(String filein) throws IOException, InterruptedException{
     FileInputStream in=new FileInputStream(filein);
     byte[] b=new byte[in.available()];
     in.read(b);
     in.close();
     bgImage=Toolkit.getDefaultToolkit().createImage(b);
     MediaTracker mt=new MediaTracker(this);
     mt.addImage(bgImage,0);
     mt.waitForAll();
    }
    public void actionPerformed(ActionEvent e){

    }
    public static void main(String[] args){
     COS newcos=new COS();
     f.setSize(825,640);
     f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     f.getContentPane().setLayout(null);
     newcos.setBounds(5,5,800,600);
     f.setLocation(10,5);
     f.getContentPane().add(newcos);
     f.setVisible(true);
    }
}

could anybody tell what's wrong?
</code></pre>
