samples=['sample1.jpg','sample2.jpg','sample3.jpg','sample4.jpg','sample5.jpg','sample6.jpg','sample7.jpg','sample8.jpg','sample9.jpg','sample10.jpg'];
sampleindex=0;
addEvent(window,'load',samplesLoad);

function samplesLoad () {
	back=document.getElementById('imgprev');
	forward=document.getElementById('imgnext');
	if (back!=null){
	back.onclick=showBck;
	forward.onclick=showFwd;
	window.img1=document.getElementById('img1');
	window.img2=document.getElementById('img2');
	window.img3=document.getElementById('img3');
	if (document.images) {
	  preload=new Image(20,20);
    for (i=0;i<samples.length;i++) {
		  preload.src='./img/samples/'+samples[i];
		}
	} else {
		for (i=0;i<samples.length;i++) {
		  window.img1.src='./img/samples/'+samples[i];
		}
	}
	window.img1.src='./img/samples/'+samples[0];
	window.img2.src='./img/samples/'+samples[1];
	window.img3.src='./img/samples/'+samples[2];
	
	}
}

function showFwd () {
	tmp=sampleindex;
	tmp=increase(tmp);
	window.img1.src='./img/samples/'+samples[tmp];
	tmp=increase(tmp);
	window.img2.src='./img/samples/'+samples[tmp];
	tmp=increase(tmp);
	window.img3.src='./img/samples/'+samples[tmp];
	sampleindex=increase(sampleindex);
	return false;
}

function showBck () {
  tmp=sampleindex;
	tmp=decrease(tmp);
	window.img1.src='./img/samples/'+samples[tmp];
	tmp=increase(tmp);
	window.img2.src='./img/samples/'+samples[tmp];
	tmp=increase(tmp);
	window.img3.src='./img/samples/'+samples[tmp];
  sampleindex=decrease(sampleindex);
  return false;
}

function increase (num) {
	if (num<(samples.length-1)) {
	  return (num+1);
	} else {
	  return 0;
	}
}

function decrease (num) {
	if (num==0) {
	  return (samples.length-1);
	} else {
	  return (num-1);
	}
}