function timeDrivenImage(){
	var now = new Date();
	h = now.getHours();
	m = now.getMonth();

/* vier jahreszeiten, wir haben aber nur zwei
	if (m > 10 || m < 2){
		month = "winter";
	} else if (m >= 2 && m < 5){
		month = "autumn";
	} else if (m >= 5 && m < 8){
		month = "summer";
	} else if (m >= 8 && m < 11){
		month = "fall";
	}
*/

	if (m > 9 || m < 4){
		month = "winter";
	}
	else {
		month = "summer";
	}	
	
	if (h >= 6 && h < 11){
		hour = "Morning";
	} else if (h >= 11 && h < 17){
		hour = "Noon";
	} else if (h >= 17  && h < 22){
		hour = "Evening";
	} else {
		hour = "Night";
	}
	
	if (document.getElementById('header')){
		document.getElementById('header').style.backgroundImage = "url(/docroot/hasena.ch/imgs/"+month+hour+".jpg)";
	}
}