private void voiceTalkButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_voiceTalkButtonActionPerformed
        // TODO add your handling code here:
        String dest = myList.getSelectedValue().toString();
        dest = dest.trim();
        if ( client.player != null )
        {
            JOptionPane.showMessageDialog(null, "你在跟別人通話中，別重啟通話",  
                            "Error", JOptionPane.ERROR_MESSAGE);
        }
        else if ( dest.equals( client.frame.getTitle() ) )
        {
             JOptionPane.showMessageDialog(null, "不能跟自己語音通話",  
                            "Error", JOptionPane.ERROR_MESSAGE);
        }
        else
        {
            client.sendMessage( "VOICE@" + dest + "@" + client.frame.getTitle() + "@" + client.getIP() );
        }
    }//GEN-LAST:event_voiceTalkButtonActionPerformed