function mouseXY(e) {
  var x = 0, y = 0;

  if (!e) e = window.event;

  if (e.pageX || e.pageY) {
    x = e.pageX;
    y = e.pageY;
  }
  else if (e.clientX || e.clientY) {
    x = e.clientX + (document.documentElement.scrollLeft || document.body.scrollLeft) - document.documentElement.clientLeft;
    y = e.clientY + (document.documentElement.scrollTop || document.body.scrollTop) - document.documentElement.clientTop;
  }

  return { "x" : x, "y" : y };
}

function centerXY() {
  return {
		"x" : parseInt(getClientWidth() / 2) + getBodyScrollLeft(),
		"y" : parseInt(getClientHeight()/ 2) + getBodyScrollTop()
	};
}

function getBodyScrollTop() {
  return (document.documentElement && document.documentElement.scrollTop) || (document.body && document.body.scrollTop);
}

function getBodyScrollLeft() {
  return (document.documentElement && document.documentElement.scrollLeft) || (document.body && document.body.scrollLeft);
}

function getClientWidth() {
  return document.compatMode=='CSS1Compat' && !window.opera?document.documentElement.clientWidth:document.body.clientWidth;
}

function getClientHeight() {
  return document.compatMode=='CSS1Compat' && !window.opera?document.documentElement.clientHeight:document.body.clientHeight;
}

function getElementPosition(elem) {
  var offsetTrail = elem;
	if (typeof(elem) != "object" && document.getElementById(elem)) offsetTrail = document.getElementById(elem);
  var offsetLeft = 0;
  var offsetTop = 0;
  while (offsetTrail) {
    offsetLeft += offsetTrail.offsetLeft;
    offsetTop += offsetTrail.offsetTop;
    offsetTrail = offsetTrail.offsetParent;
  }
  if (navigator.userAgent.indexOf("Mac") != -1 && 
    typeof document.body.leftMargin != "undefined") {
    offsetLeft += document.body.leftMargin;
    offsetTop += document.body.topMargin;
  }
  return {left:offsetLeft, top:offsetTop};
}