function getposOffset(overlay, offsettype) {
	var totaloffset = (offsettype == "left") ? overlay.offsetLeft : overlay.offsetTop;
	var parentEl = overlay.offsetParent;
	while (parentEl != null) {
		totaloffset = (offsettype == "left") ? totaloffset + parentEl.offsetLeft : totaloffset + parentEl.offsetTop;
		parentEl = parentEl.offsetParent;
	}
	return totaloffset;
}
var LastDiv;
function overlay(curobj, subobjstr, opt_position) {
	if (LastDiv) overlayclose(LastDiv);
	if (document.getElementById) {
		var subobj = document.getElementById(subobjstr);
		subobj.style.display = (subobj.style.display != "block") ? "block" : "none";
		var xpos = getposOffset(curobj, "left");
		var ypos = getposOffset(curobj, "top");
		if ((typeof opt_position != "undefined") && (opt_position.indexOf("right") != -1)) { 
			xpos -= (subobj.offsetWidth - curobj.offsetWidth);
		} else {
			xpos += 10; 
		}
		if ((typeof opt_position != "undefined") && (opt_position.indexOf("bottom") != -1))  {
			ypos += curobj.offsetHeight;
		}
		subobj.style.left = xpos + "px";
		subobj.style.top = ypos + "px";
		LastDiv = subobjstr;
		return false;
	} else return true;
}

function overlayclose(subobj) {
	document.getElementById(subobj).style.display = "none";
}