$.fn.x = function(n) {
 var result = null;
 this.each(function() {
 var o = this;
 if (n === undefined) {
 var x = 0;
 if (o.offsetParent) {
 while (o.offsetParent) {
 x += o.offsetLeft;
 o = o.offsetParent;
 }
 }
 if (result === null) {
 result = x;
 } else {
 result = Math.min(result, x);
 }
 } else {
 o.style.left = n + 'px';
 }
 });
 return result;
};

$.fn.y = function(n) {
 var result = null;
 this.each(function() {
 var o = this;
 if (n === undefined) {
 var y = 0;
 if (o.offsetParent) {
 while (o.offsetParent) {
 y += o.offsetTop;
 o = o.offsetParent;
 }
 }
 if (result === null) {
 result = y;
 } else {
 result = Math.min(result, y);
 }
 } else {
 o.style.top = n + 'px';
 }
 });
 return result;
};