function prepareSlideshow() {
	if (!document.getElementsByTagName) return false;
	if (!document.getElementById) return false;
	if (!document.getElementById("main_nav")) return false;
	if (!document.getElementById("logo_scroll")) return false;
	
	var preview = document.getElementById("logo_scroll");
	preview.style.position = "absolute";
	
	var list = document.getElementById("main_nav");
	var links = list.getElementsByTagName("a");
	
	links[0].onmouseover = function() {
		moveElement("logo_scroll", 0,-0,20);
	}
	links[1].onmouseover = function() {
		moveElement("logo_scroll", 0,-400,20);
	}
	links[2].onmouseover = function() {
		moveElement("logo_scroll", 0,-800,20);
	}
	links[3].onmouseover = function() {
		moveElement("logo_scroll", 0,-1200,20);
	}
	links[4].onmouseover = function() {
		moveElement("logo_scroll", 0,-1600,20);
	}
}

function moveElement(elementID, final_x, final_y, interval) {
	if (!document.getElementById) return false;
	if (!document.getElementById(elementID)) return false;
	var elem = document.getElementById(elementID);
	if (elem.movement) {
		clearTimeout(elem.movement);
	}
	if (!elem.style.left) {
		elem.style.left = "0px";
	}
	if (!elem.style.top) {
		elem.style.top = "0px";
	}
	var xpos = parseInt(elem.style.left);
	var ypos = parseInt(elem.style.top);
	
	if (xpos == final_x && ypos == final_y) {
		return true;
	}
	if (xpos < final_x) {
		var dist = Math.ceil((final_x - xpos)/10);
		xpos = xpos + dist;
	}
	if (xpos > final_x) {
		var dist = Math.ceil((xpos - final_x)/10);
		xpos = xpos - dist;
	}
	if (ypos < final_y) {
		var dist = Math.ceil((final_y - ypos)/10);
		ypos = ypos + dist;
	}
	if (ypos > final_y) {
		var dist = Math.ceil((ypos - final_y)/10);
		ypos = ypos - dist;
	}
	
	elem.style.left = xpos + "px";
	elem.style.top = ypos + "px";
	var repeat = "moveElement('"+elementID+"',"+final_x+","+final_y+","+interval+")";
	elem.movement = setTimeout(repeat,interval);
}

function addLoadEvent(func) {
	var oldonload = window.onload;
	if (typeof window.onload != 'function') {
		window.onload = func;
	} else {
		window.onload = function() {
			if (oldonload) {
				oldonload();
			}
			func();
		}
	}
}
addLoadEvent(prepareSlideshow);