/* 

Copyright 2009 grafitecture GmbH

*/
//var bgImgNr = 1 + Math.floor(Math.random() * 2);
bgImgNr = 0;
function switchBackgroundImage(){
	var imgCount = 12;
	var newImgUrl = "url(fileadmin/user_upload/home/bg_"+(1+bgImgNr%imgCount)+".jpg)";
	$('content_header').style.backgroundImage = newImgUrl;
	new Effect.Opacity('ch_transition', {
		duration:2,
		from:1.0,
		to:0.0,
		afterFinish: function () {
			$('ch_transition').style.backgroundImage = newImgUrl;
			new Effect.Opacity('ch_transition', {	
				duration:0.5,
				from:0.0,
				to:1.0
			});
		}
	});
	++bgImgNr;

}
Event.observe(window, 'load', function() {
	switchBackgroundImage();
	new PeriodicalExecuter(switchBackgroundImage, 7);
});