//////////////////////////////////////////////////////////////////////////////
/*********   UNOBSTRUSIVE ROLLOVER-SCRIPT   *********************************/
/*********   Autorin: Franziska Mälzer   ************************************/
/*********   http://die.netzspielwiese.de   *********************************/
//////////////////////////////////////////////////////////////////////////////

function createRollovers(ulId) {
	if( document.getElementById ) {
		var	preloadImageList = new Array(); // enthaelt die vorgeladenen Bilder
		var pictures_ul = document.getElementById(ulId);
		for (i = 0; i < pictures_ul.childNodes.length; i++) {
			var pictures_li = pictures_ul.childNodes[i];
			// wenn Knotentyp ein ELEMENT ist, also <li> ausgewaehlt //
			if (pictures_li.nodeType == 1) {
				var pictures_a = pictures_li.firstChild;
				pictures_a.onmouseover = function() { wechseln(this, "an"); };
				pictures_a.onfocus = function() { wechseln(this, "an") };
				pictures_a.onmouseout = function() { wechseln(this, "aus") };
				pictures_a.onblur = function() { wechseln(this, "aus") };
				// Hover-Bilder vorausladen
				var imgSrc = pictures_a.getElementsByTagName('img')[0].src;
				var newImgSrc = imgSrc.substring(0,imgSrc.length - 4);
				// GIF
				if (imgSrc.indexOf('.gif') > -1) {
					var newImgSrc = newImgSrc + "_h.gif";
				}	else { // JPG
					var newImgSrc = newImgSrc + "_h.jpg";
				}
				preloadImageList[i] = new Image();
				preloadImageList[i].src = newImgSrc;
			}
		}
	}
}

function wechseln(objekt, schalter) {
	var pictures_img = objekt.getElementsByTagName('img')[0];
	var pictures_img_url = pictures_img.src;
	pictures_img_url_laenge_ohne_gif = pictures_img_url.length - 4;
	pictures_img_url_ohnegif = pictures_img_url.substring(0,pictures_img_url_laenge_ohne_gif);
	
	if (schalter == "an") {
		// wenn Bild grau ist
		if (pictures_img_url.indexOf('_h') == -1) {
			// GIF-Bilder
			if (pictures_img_url.indexOf('.gif') > -1 ) {
				pictures_img.src = pictures_img_url_ohnegif + "_h.gif";
			} else {
			// JPG-Bilder
				pictures_img.src = pictures_img_url_ohnegif + "_h.jpg";
			}
		}
	} else if(schalter == "aus") {
		// wenn Bild bunt ist
		if (pictures_img_url.indexOf('_h') > -1) {
			// GIF
			if (pictures_img_url.indexOf('.gif') > -1 ) {
				pictures_img.src = pictures_img_url_ohnegif.substring(0, (pictures_img_url_laenge_ohne_gif-2)) + ".gif";
			} else { // JPG
				pictures_img.src = pictures_img_url_ohnegif.substring(0, (pictures_img_url_laenge_ohne_gif-2)) + ".jpg";
			}
		}
	}
}