// JavaScript Document


// --- Bannerbilder laden

imgPreloadArray = new Array(); // Pfade zu den Bilder
imgPreloadArray[0] = "js_banner_img/1.jpg";
imgPreloadArray[1] = "js_banner_img/2.jpg";
imgPreloadArray[2] = "js_banner_img/3.jpg";
imgPreloadArray[3] = "js_banner_img/4.jpg";
imgPreloadArray[4] = "js_banner_img/5.jpg";
imgPreloadArray[5] = "js_banner_img/6.jpg";
imgPreloadArray[6] = "js_banner_img/7.jpg";
imgPreloadArray[7] = "js_banner_img/8.jpg";
imgPreloadArray[8] = "js_banner_img/9.jpg";
imgPreloadArray[9] = "js_banner_img/10.jpg";

imgArray = new Array(); // Bildobjekte im Array
countImg = 1; // gibt die Position des Zeigers im Array an

a=1; // Schrittweite
t=60; // Tempo ms

function preloadImages() {
	for (i = 0; i < imgPreloadArray.length; i++) {
		var Bild = new Image();
		Bild.src = imgPreloadArray[i];
		
		imgArray[i] = Bild.src;
	}
	
	window.setTimeout("startAnimation()", 250);
}

function fadeIn(objId, opacity) {
	if(document.getElementById) {
		obj = document.getElementById(objId);
		if(opacity <= 100) {
			setOpacity(obj, opacity);
			opacity += 10;
			window.setTimeout("fadeIn('" + objId + "', " + opacity + ")", 50);
		}
	}
}

function fadeOut(objId, opacity) {
	if(document.getElementById) {
		obj = document.getElementById(objId);
		if(opacity >= 0) {
			setOpacity(obj, opacity);
			opacity -= 10;
			window.setTimeout("fadeOut('" + objId + "', " + opacity + ")", 50);
		}
		else {
			document.images['js_banner_animation'].src = imgArray[countImg]; // nächstes Bild zuweisen
			animation.top = 0+'px';
			countImg++;
			if(countImg == imgPreloadArray.length) countImg = 0; // zurücksetzen
			
			fadeIn('js_banner_animation', 0);
		}
	}
}

function setOpacity(obj, opacity) {
	opacity = (opacity == 100) ? 99.999 : opacity;
	// IE/Win
	obj.style.filter = "alpha(opacity:" + opacity + ")";
	// Safari < 1.2, Konqueror
	obj.style.KHTMLOpacity = opacity/100;
	// ältere Mozilla und Firefox
	obj.style.MozOpacity = opacity/100;
	// Safari 1.2, neuere Firefox und Mozilla, CSS3
	obj.style.opacity = opacity/100;
}

function startAnimation() {
	y = 0; // aktuelle Y-Pos
	img_height = document.images['js_banner_animation'].height;
	box_height = 150; // Höhe der DIV-Box
	animation = document.getElementById('js_banner_animation').style;
	
	window.setTimeout("movedown()", 500);
}

function checkImgComplete() { // mit dem Preload beginnen, wenn das Startbild geladen wurde
	if(document.images['js_banner_animation'].complete) {
		preloadImages();
	}
	else {
		window.setTimeout('checkImgComplete()', 250);
	}
}

// --- Bannerbilder scrollen

function movedown() {	
	if(y >= box_height-img_height+a) {
		y -= a;
		animation.top = y+'px';
		window.setTimeout('movedown()', t);
	}
	else {
		fadeOut('js_banner_animation', 100); // aktuelles Bild ausblenden
		window.setTimeout("startAnimation()", 750);
	}
}

// --- ONLOAD

window.onload = function() {
	if(document.getElementById('js_banner_animation')) {
		checkImgComplete();
	}
}