var currentPic = "bigPic1";

function showSection(id){
	document.getElementById(id).style.backgroundColor="#f4f4f4";

	document.getElementById("initial").style.display="none";
	document.getElementById("next").style.display="none";

	switch (id){
		case "leftArrow" : document.getElementById("initial").style.display="block";
			break;
		case "rightArrow" :
			html = document.getElementById("next").innerHTML;
            if (html.replace(/^\s*|\s*$/g,"") != '') {
                document.getElementById("next").style.display="block";
            } else {
                document.getElementById("initial").style.display="block";
            }
			break;
	}
}

function swap(id)
{
var clickedThumb = id.substring(5,6);
var showBigPic = "bigPic" + clickedThumb;
document.getElementById(currentPic).style.display="none"; // hide the current big pic.
document.getElementById(showBigPic).style.display="block"; //show the new big pic.
currentPic = showBigPic; 
}