private void jMenuItem4ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jMenuItem4ActionPerformed
        Desktop dt = Desktop.getDesktop();
        try
        {
            dt.open( new File("help.html") );
        } catch (IOException e) {//exception handling?
            }
    }//GEN-LAST:event_jMenuItem4ActionPerformed