function kurs(art)
{
var art_array = new Array("grundlagen", "foto", "goodies");
for (i in art_array)
	{
	 if (art_array[i] != art)
	 	{
	 	 obj = document.getElementById(art_array[i]);
		 obj.style.visibility = "hidden";
		 obj.style.display = "none";
	 	};
	};
obj = document.getElementById(art);
obj.style.visibility = "visible";
obj.style.display = "block";
}

function markLink(xy)
{
linkColorBackground = "#4e567d";
divObjParent = document.getElementsByTagName("li");
max = divObjParent.length;
for (i=0; i<max; i++)
	{
	 divObj = divObjParent[i];
	 aObj = divObj.firstChild;
	 while (aObj.nodeType == 3) {aObj = aObj.nextSibling;};
	 text = aObj.firstChild.data;
	 link = aObj.href;
	 callUrl = document.URL;
	 len = 9 ; /* Länge von "index.php" */
	 datei = link.substr(link.length - len , len);
	 if (  (link == callUrl) || ((datei == "index.php") && (link.substr(0,link.length-len) == callUrl))  )
		{
		 weg = divObj.removeChild(aObj);
		 textNode = document.createTextNode(text);
		 newDivText = document.createElement("span");
		 newDivText.className = "navitext";
		 newDivText.appendChild(textNode);
		 divObj.appendChild(newDivText);
		 divObj.style.backgroundColor = linkColorBackground;
		};
	};
}