var PicPath = "";
var PicIndex = 0;
var PicNum = 0;

function pic_update() {
	if(document.all['slide']) {
		document.all['slide'].innerHTML = '<IMG src="'+PicPath+PicIndex+'.jpg">';
		document.all['slide_counter'].innerHTML = PicIndex+"/"+PicNum;
	} else {
		setTimeout(500, 'pic_update();');
	}
}

function pic_first() {
  PicIndex = 1;
  pic_update();
};

function pic_last() {
  PicIndex = PicNum;
  pic_update();
};

function pic_next() {
  PicIndex++;
  if(PicIndex > PicNum) PicIndex = 1;
  pic_update();
};

function pic_prev() {
  PicIndex--;
  if(PicIndex < 1) PicIndex = PicNum;
  pic_update();
};