var imgTable    = new Array();
var imgPosition = -1;

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

function prevImage() {
	if (imgPosition > 0) {
		imgPosition--;
		changeImg();
	} else {
		imgPosition = imgTable.length-1;
		changeImg();
	}		
}

function nextImage() {
	if (imgPosition < imgTable.length-1) {
		imgPosition++;
		changeImg();
	} else {
		imgPosition = 0;
		changeImg();
	}
}



function changeImg() {
	tempImage = new Image();
	tempImage.src = imgTable[imgPosition][0];

	document.images.imgSlide.src = imgTable[imgPosition][0];

	imageWidth  = tempImage.width;
	imageHeight = tempImage.height;
	if (imageWidth > imageHeight) {
		if (imageWidth > 480) {
			imageHeight = (480 * imageHeight) / imageWidth;
			imageWidth = 480;
		}
	} else {
		if (imageHeight > 300) {
			imageWidth = (300 * imageWidth) / imageHeight;
			imageHeight = 300;
		}
	}

	document.images.imgSlide.width = imageWidth;
	document.images.imgSlide.height = imageHeight;
	document.getElementById('imgCaption').innerHTML = imgTable[imgPosition][1];
	document.getElementById('imgCount').innerHTML = imgPosition+1;
	document.getElementById('imgTotal').innerHTML = imgTable.length;
}


function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  }
  else {
    window.onload = function() {
      if (oldonload) {
        oldonload();
      }
      func();
    }
  }
}

addLoadEvent(nextImage);