//GingerBread
dialog = new AlertDialog.Builder(this,AlertDialog.THEME_TRADITIONAL);//Holo Dark
dialog = new AlertDialog.Builder(this,AlertDialog.THEME_DEVICE_DEFAULT_DARK);
//Holo Light
dialog = new AlertDialog.Builder(this,AlertDialog.THEME_HOLO_LIGHT);
//Material Dark
setTheme(android.R.style.Theme_Material);
//Material Light
setTheme(android.R.style.Theme_Material_Light);
//Default Dark
dialog = new AlertDialog.Builder(this,AlertDialog.THEME_DEVICE_DEFAULT_DARK);
//Default light
dialog = new AlertDialog.Builder(this,AlertDialog.THEME_DEVICE_DEFAULT_LIGHT);