// JavaScript Document
var thmbPreloads = new Array();
var imgPreloads = new Array();
var numImages = 11;
var numOnScreen = 5;
var firstImage = 1;

function setImageEnlargements() {
	//Preload all thumbnails
	for(ixT=1; ixT<=numImages; ixT++){ 
		thmbPreloads[ixT] = new Image();
		thmbPreloads[ixT].src = "images/thumbs/" + ixT + ".jpg";
	}
	
	var imgPrefix = "thumb_";
	var imgs = document.getElementsByTagName('img');
	for(i=0; i<imgs.length; i++){ 
		if (imgs[i].id) {
			if (imgs[i].id.substring(0,imgPrefix.length) == imgPrefix) {
				imgs[i].onmouseover=function(){showLarge(this.src);};
				
				imageLargeName = imgs[i].src.substring(imgs[i].src.lastIndexOf('/') + 1);
				imageLargeSource = "images/large/" + imageLargeName;	
				imgPreloads[i] = new Image();
				imgPreloads[i].src = imageLargeSource;
			}
		}
	}
}


function moveThumbnails(direction) {
	var topImage = document.getElementById("thumb_1").src
	topImageName = topImage.substring(topImage.lastIndexOf('/') + 1);
	topImageName = topImageName.substring(0,topImageName.indexOf("."));	//Remove .gif
	
	if(direction ==1) {
		if (numImages - topImageName < numOnScreen) {return;}
	} else {
		if(topImageName == 1) {return;}	
	}
	
	for(ixT=0; ixT<5; ixT++) {
		currSrc = document.getElementById("thumb_"+(ixT+1)).src;
		currSrc = currSrc.substring(currSrc.lastIndexOf('/') + 1);
		currSrc = currSrc.substring(0,currSrc.indexOf("."));	//Remove .gif
		newSrc = parseInt(currSrc) + direction;
		document.getElementById("thumb_"+(ixT+1)).src = "images/thumbs/"+newSrc+".jpg";
	}

	//Check image to use for Up arrow
	//alert(topImageName)
	if(direction == -1 && topImageName == 2) { //i.e. top image is now 1
		document.getElementById("moveLeft").src = "images/arrowleft_end.gif";
	} else {
		document.getElementById("moveLeft").src = "images/arrowleft.gif";		
	}
	
	if (topImageName == numImages - numOnScreen) {
		document.getElementById("moveRight").src = "images/arrowright_end.gif";
	} else {
		document.getElementById("moveRight").src = "images/arrowright.gif";		
	}

	//Refresh Large Image
	firstImage = parseInt(topImageName) + direction;
	showLarge(parseInt(topImageName)+direction+2+".jpg");
}


function showLarge(imageName) {
	imageToShow = imageName.substring(imageName.lastIndexOf('/') + 1);
	imageNum = imageToShow.substring(0,imageToShow.indexOf("."));	//Remove .gif
	var thumbToHighlight = imageNum - firstImage + 1;
	imageSource = "images/large/" + imageToShow;	
	document.getElementById("portfolioLarge").src = imageSource;
	for(ixH=1;ixH<=numOnScreen;ixH++) {
		document.getElementById("thumb_" + ixH).className = "thumbnail";
	}
	document.getElementById("thumb_" + thumbToHighlight).className = "activeThumbnail";
}