function onSpanOver(obj){
	var imgobj = document.getElementById("imganfahrt");
	var newbild = new Image();
	if(obj.id == "id1"){
		newbild.src="gfx/anfahrt1.gif"
		imgobj.src=newbild.src;
	}
	if(obj.id == "id2"){
		newbild.src="gfx/anfahrt2.gif"
		imgobj.src=newbild.src;
	}
	if(obj.id == "id3"){
		newbild.src="gfx/anfahrt3.gif"
		imgobj.src=newbild.src;
	}
}