var photos=new Array();
var captions=new Array();
var photonumber=new Array();
var which=0;

var preloadedimages=new Array()
for (i=0;i<photos.length;i++){
preloadedimages[i]=new Image()
preloadedimages[i].src=photos[i]
}

function backward(){
if (which>0){
which--;
document.images.photoslider.src=photos[which];
document.getElementById("caption").innerHTML=captions[which];
document.getElementById("number").innerHTML=photonumber[which];
}
}

function forward(){
if (which<photos.length-1){
which++;
document.images.photoslider.src=photos[which];
document.getElementById("caption").innerHTML=captions[which];
document.getElementById("number").innerHTML=photonumber[which];
}
}