public void actionPerformed( ActionEvent evt )
    { 
      evt.getActionCommand();

      //handels the button events and sets flags
      if(((JButton)evt.getSource()).getText().equals("Stop"))
      {
        runProgram = false;
      }
      if(((JButton)evt.getSource()).getText().equals("Start"))
      {
        runProgram = true;
      }
      if(((JButton)evt.getSource()).getText().equals("Clear"))
      {
        isClear = true;
      }
    }//end actionPerformed()