function prepareGallery() {
	if (!document.getElementsByTagName) return false;
	if (!document.getElementById) return false;
	if (!document.getElementById("gallery")) return false;
	var gallery = document.getElementById("gallery");
	var links = gallery.getElementsByTagName("a");
	for ( var i=0; i < links.length; i++) {
		links[i].onclick = function() {
			showPic(this);
			return false;
		}
	}
}

function showPic(whichpic) {
	if (!document.getElementById("placeholder")) return true;
	// move highlight
	var picID = whichpic.getAttribute("id");
	if (picID == "pic1") {
		picTop = "10px";
		picLeft = "501px";
	}
	if (picID == "pic2") {
		picTop = "10px";
		picLeft = "625px";
	}
	if (picID == "pic3") {
		picTop = "134px";
		picLeft = "501px";
	}
	if (picID == "pic4") {
		picTop = "134px";
		picLeft = "625px";
	}
	if (picID == "pic5") {
		picTop = "257px";
		picLeft = "501px";
	}
	if (picID == "pic6") {
		picTop = "257px";
		picLeft = "625px";
	}
	var hilight = document.getElementById("thumbhi");
	hilight.style.top = picTop;
	hilight.style.left = picLeft;
	// change pic
	var source = whichpic.getAttribute("href");
	var placeholder = document.getElementById("placeholder");
	placeholder.setAttribute("src",source);
}