var numImages = 3;
var selectedIdx;

function DisplayFooterImg()
{
	selectedIdx = Math.floor((Math.random()*numImages)+1);
	document.write('<img name="footer_img" src="'+footerImgSrc(selectedIdx)+'" width="375" height="95" border="0"><br/>');
}
function footerImgSrc(idx)
{
	return 'images/footer_message'+ idx +'.gif';
}

function DisplayNumButtons()
{
	for(var i=1; i<=numImages; i++)
	{
		document.write('<img name="num'+i+'" src="'+imgSrc(i)+'" alt="'+i+'" onmouseover="ImgHover('+i+')" onmouseout="ImgOut('+i+')" onclick="ImgClick('+i+')"/>' + "\n");
	}
}

function imgSrc(idx)
{
	if(idx==selectedIdx)
		return "images/num"+idx+"a.gif";
	else
		return "images/num"+idx+".gif";
}

function ImgHover(idx)
{
	document.images['num'+idx].src = "images/num"+idx+"a.gif";
}
function ImgOut(idx)
{
	document.images['num'+idx].src = imgSrc(idx);
}

function ImgClick(idx)
{
	document.images['footer_img'].src = footerImgSrc(idx);
	selectedIdx = idx;
	
	for(var i=1; i<=numImages; i++)
	{
		document.images['num'+i].src = imgSrc(i);
	}
}