function getSeasonalImg() {
	today = new Date();
	var d = today.getDate();
	var m = today.getMonth();
	var s;
	switch(m) {
		case 0:
		case 1:
			s=3;
			break;
		case 2:
			s=(d<21)?3:0;
			break;
		case 3:
		case 4:
			s=0;
			break;
		case 5:
			s=(d<21)?0:1;
			break;
		case 6:
		case 7:
			s=1;
			break;
		case 8:
			s=(d<23)?1:2;
			break;
		case 9:
		case 10:
			s=2;
			break;
		case 11:
			s=(d<22)?2:3;
			break;
	}
	window.document.getElementById('season').src="/img/season" + s + ".jpg";
}