var imgRotateInterval;
var pathToBig = "images/homepage/big/";
var imgCount = 12;
var numOfSets = 3;
var currentImg = 0;
var currentRowSet = 1;

function randomizeImg(specific) {
	var randomNum;
	if (specific)
		randomNum = specific; 
	else
		randomNum = Math.floor(Math.random() * imgCount - 1);
	
	if (randomNum < 5)
		newImgGroup(false,1);
	else if (randomNum >= 5 && randomNum < 9)
		newImgGroup(false,2);
	else if (randomNum >= 9)
		newImgGroup(false,3);
		
	var initImg = "hmimg" + randomNum;
	changeStyle(document.getElementById(initImg));
}

function changeStyle(imgObj, action) {
	if(window.event)
		var eType = event.type;
	else if(action!=null)
		var eType = action;
	var domImg = document.getElementById(imgObj.id);
	var imageNum = getImgNum(domImg.id);
	
	if (imageNum != currentImg && eType!=null) {
		switch (eType) {
			case "mouseover":
				domImg.style.cursor = "pointer";
				domImg.className = "homeimg-over";
				break;
			case "mouseout":
				domImg.style.cursor = "default";
				domImg.className = "homeimg-default";
				break;
			case "click":
				var curImgTemp = "hmimg" + currentImg;
				document.getElementById(curImgTemp).className = "homeimg-default";
				
				domImg.className = "homeimg-selected";
				currentImg = imageNum;
				changeBig(imageNum);
				break;
			default:
				domImg.className = "homeimg-selected";
				currentImg = imageNum;
				changeBig(imageNum);
				break;
		}
	}
	else {
		domImg.className = "homeimg-selected";
		currentImg = imageNum;
		changeBig(imageNum);
	}
}

function getImgNum(theid) {
	var t = theid;
	var s = t.substring(5);
	return s
}

function changeBig(imageNum) {
	var domBigImg = document.getElementById("centerImg");
	
	var newImg = new Image();
		newImg.src = pathToBig + imageNum + ".jpg";
	domBigImg.src = newImg.src;
}

function newImgGroup(dir,opendirect) {
	var newRowSet;
	
	if (!opendirect) {
		newRowSet = currentRowSet;
		switch (dir) {
			case "up":
				newRowSet++;
				break;
			case "down":
				newRowSet--;
				break;
		}
		
		if (newRowSet > numOfSets)
			newRowSet = 1;
		else if (newRowSet < 1)
			newRowSet = numOfSets;
	}
	else
		newRowSet = opendirect;
	
	var oldRowToHide = "picrow" + currentRowSet;
	var newRowToShow = "picrow" + newRowSet;
	
	//alert(oldRowToHide + " " + newRowToShow);
	document.getElementById(oldRowToHide).style.display = 'none';
	document.getElementById(newRowToShow).style.display = 'block';
	
	currentRowSet = newRowSet;
}