T = new TimerTask() {
	@Override
	public void run() {
		runOnUiThread(new Runnable() {
			@Override
			public void run() {
				if (edittext1.getText().toString().equals("")) {
					button1.setBackground(new GradientDrawable() { public GradientDrawable getIns(int a, int b, int c, int d) { this.setCornerRadius(a); this.setStroke(b, c); this.setColor(d); return this; } }.getIns((int)20, (int)5, 0xFFBDBDBD, 0xFF7986CB));
				}
				else {
					button1.setBackground(new GradientDrawable() { public GradientDrawable getIns(int a, int b, int c, int d) { this.setCornerRadius(a); this.setStroke(b, c); this.setColor(d); return this; } }.getIns((int)20, (int)5, 0xFFBDBDBD, 0xFF3D5AFE));
				}
			}
		});
	}
};
_timer.scheduleAtFixedRate(T, (int)(0), (int)(10));
button1.setOnClickListener(new View.OnClickListener() {
	@Override
	public void onClick(View _view) {
		if (edittext1.getText().toString().equals("")) {
			((EditText)edittext1).setError("မှားနေပါ သည်");
		}
	}
});