var index=0;
var prefix="http://www.unix-ag.uni-kl.de/~fischer/photos/";
images=new Array();
images[0]=new Image();
images[0].src=prefix+"20091011-Reiten-06.jpg";
images[1]=new Image();
images[1].src=prefix+"20091011-Reiten-13.jpg";
images[2]=new Image();
images[2].src=prefix+"20091011-Reiten-16.jpg";
images[3]=new Image();
images[3].src=prefix+"20091011-Reiten-17.jpg";
images[4]=new Image();
images[4].src=prefix+"20091011-Reiten-22.jpg";
images[5]=new Image();
images[5].src=prefix+"20091011-Reiten-24.jpg";

function nextPhoto(){
++index;
if (index>=images.length) { index=0; }
document.photography.src=images[index].src;
}

function prevPhoto(){
--index;
if (index<0) { index=images.length-1; }
document.photography.src=images[index].src;
}