myHandler = new Handler() {
            public void handleMessage(Message msg){
                super.handleMessage(msg);

                if(playSequence){

                    button1.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.btn_default));
                    button2.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.btn_default));
                    button3.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.btn_default));
                    button4.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.btn_default));

                    if (setDefault)
                    {
                        button1.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.btn_default));
                        button2.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.btn_default));
                        button3.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.btn_default));
                        button4.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.btn_default));
                    }
                    else
                    {
                        switch(sequenceToCopy[elementToPlay]){
                            case 1:
                                button1.startAnimation(wobble);
                                button1.setBackgroundColor(Color.RED);
                                // play a sound
                                soundPool.play(sample1, 1, 1, 0, 0, 1);
                                break;

                            case 2:
                                button2.startAnimation(wobble);
                                button2.setBackgroundColor(Color.BLUE);
                                // play a sound
                                soundPool.play(sample2, 1, 1, 0, 0, 1);
                                break;

                            case 3:
                                button3.startAnimation(wobble);
                                button3.setBackgroundColor(Color.YELLOW);
                                // play a sound
                                soundPool.play(sample3, 1, 1, 0, 0, 1);
                                break;

                            case 4:
                                button4.startAnimation(wobble);
                                button4.setBackgroundColor(Color.GREEN);
                                // play a sound
                                soundPool.play(sample4, 1, 1, 0, 0, 1);
                                break;
                            case 5:
                                button1.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.btn_default));
                                button2.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.btn_default));
                                button3.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.btn_default));
                                button4.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.btn_default));
                                break;

                        }
                    }

                    if (setDefault)
                    {
                        setDefault = false;
                        sequenceFinished();
                    }
                    else
                    {
                        elementToPlay++;
                        if (elementToPlay == difficultyLevel)
                        {
                            setDefault = true;
                        }
                    }
                }
                myHandler.sendEmptyMessageDelayed(0,900);
            }
        }; //end of thread