window.onload = function() {
	page_init();
}

function page_init() {
	var objAreaElements = document.getElementsByTagName("area");
	for (i=0; i<objAreaElements.length; i++) {
		var currArea = objAreaElements[i];
		currArea.onmouseover = function() {
			swapCaption(this.id);
		}
		currArea.onmouseout = function() {
			swapCaption("caption_default_v3");
		}
	}
}

function swapCaption(strImageName) {
	document.getElementById("caption").src = "images/" + strImageName + ".gif";
}