var PICS_BASE_URL = "images/";
var PICS = [
	"pic_1.jpg",
	"pic_2.jpg",
	"pic_3.jpg"
];
var index = 0;

function startRotation(iInterval){
	if(document.getElementById("slogan")){
		var interval = setInterval("imageRotation(document.getElementById('slogan'))", iInterval*1000);
	}
}

function imageRotation(eTarget){
	index ++;
	if(index > 2){
		index = 0;
	}
	if(eTarget.filters){
		eTarget.filters[0].apply();
	}
	eTarget.style.backgroundImage = "url(" + PICS_BASE_URL + PICS[index] + ")";
	if(eTarget.filters){
		eTarget.filters[0].play();
	}
}

function preloadImages(aImages){
	for(var i=0; i<aImages.length; i++){
		preloadImage(aImages[i]);
	}
}

function preloadImage(sImage){
	var img = new Image();
	img.src = PICS_BASE_URL + sImage;
}