// Constants
var GALLERY_PATH='gallery/';
var IMG_PER_PAGE=4;
// Variables
var topImageNum=1;
var currImageOffset=1;
var imageArray=new Array();

function createImageObject(index,imgCaption,imgSmall,imgMain,width,height)
{
	imageArray[index]=new Object(imgCaption);
	imageArray[index].smallImage=imgSmall;
	imageArray[index].mainImage=imgMain;
	imageArray[index].mainWidth=width;
	imageArray[index].mainHeight=height;
}

function setElemVisibility(elemId,isVisible)
{
	var elem=document.getElementById(elemId);
	if(isVisible)
	{
		elem.style.visibility="visible";
	}
	else
	{
		elem.style.visibility="hidden";
	}
}

function pageSelect(dir)
{
	if(dir==0)
	{
		topImageNum=1;
	}
	else if(dir>0 && topImageNum+IMG_PER_PAGE<=imageArray.length)
	{
		topImageNum+=IMG_PER_PAGE;
	}
	else if(dir<0 && topImageNum>IMG_PER_PAGE)
	{
		topImageNum-=IMG_PER_PAGE;
	}
	setElemVisibility('PrevLink', (topImageNum>IMG_PER_PAGE));
	setElemVisibility('NextLink', (topImageNum+IMG_PER_PAGE<=imageArray.length));

	var i, imgElem;
	for(i=1;i<=IMG_PER_PAGE;i++)
	{
		if((topImageNum-1)+(i-1)<imageArray.length)
		{
			imgElem=document.getElementById('SmallImage'+i);
			imgElem.src=GALLERY_PATH+imageArray[(topImageNum-1)+(i-1)].smallImage;
			imgElem.alt=imageArray[(topImageNum-1)+(i-1)];
			setElemVisibility('DataCell'+i, true);
		}
		else
		{
			setElemVisibility('DataCell'+i, false);
		}
	}
	imageSelect(1);
}

function imageSelect(imageOffset)
{
	var dataCell=document.getElementById('DataCell'+imageOffset);
	dataCell.className="ImageCellSelected";
	if(currImageOffset!=imageOffset)
	{
		dataCell=document.getElementById('DataCell'+currImageOffset);
		dataCell.className="ImageCellNormal";
	}
	currImageOffset=imageOffset;

	//alert(imageArray[currImageOffset-1]+' '+imageArray[currImageOffset-1].smallImage+' '+imageArray[currImageOffset-1].mainImage);
	var imgElem=document.getElementById('MainImage');
	imgElem.src=GALLERY_PATH+imageArray[(topImageNum-1)+(currImageOffset-1)].mainImage;
	imgElem.width=imageArray[(topImageNum-1)+(currImageOffset-1)].mainWidth;
	imgElem.height=imageArray[(topImageNum-1)+(currImageOffset-1)].mainHeight;
}

function imageHilite(imageOffset)
{
	var dataCell=document.getElementById('DataCell'+imageOffset);
	dataCell.className="ImageCellHilite";
}

function imageReset(imageOffset)
{
	var dataCell=document.getElementById('DataCell'+imageOffset);
	if(currImageOffset==imageOffset)
	{
		dataCell.className="ImageCellSelected";
	}
	else
	{
		dataCell.className="ImageCellNormal";
	}
}