function getScreenRes(){
	
	if (screen.width == 1920)
	{
	 document.body.style.backgroundImage = 'url("IMG/sfondoAll/1920.jpg")';
	}
	else if (screen.width == 1680 || screen.width == 1440 || screen.width == 1400 || screen.width >= 1300)
	{
	  document.body.style.backgroundImage = 'url("IMG/sfondoAll/1680.jpg")';
	}
	
}