private void jgobuttonActionPerformed(java.awt.event.ActionEvent evt) {

           // command we want to run
        String cmd = jcommandlabel.getText();

        class DontEverDoThis implements Runnable {
            private final String cmd;

            DontEverDoThis(final String cmd) {
                this.cmd = cmd;
            }

            @Override
            public void run() {
                try {
                    Process p = Runtime.getRuntime().exec(cmd);
                    int i;
                    InputStream in =  p.getInputStream();

                    while((i = in.read()) != -1) {
                        System.err.print(i);
                    }

                } catch(Exception E) { E.printStackTrace(); }
            }
        }

        Thread nt = new Thread(new DontEverDoThis(cmd));
        nt.start();