function c(){
   var objTop = getOffsetTop(document.getElementById("d"));//对象x位置  var objLeft = getOffsetLeft(document.getElementById("d"));//对象y位置  var mouseX = event.clientX+document.body.scrollLeft;//鼠标x位置  var mouseY = event.clientY+document.body.scrollTop;//鼠标y位置 //计算点击的相对位置  var objX = mouseX-objLeft;  var objY = mouseY-objTop;  clickObjPosition = objX + "," + objY;  alert(clickObjPosition); } function getOffsetTop(obj){
      var tmp = obj.offsetTop;     var val = obj.offsetParent;     while(val != null){
          tmp += val.offsetTop;         val = val.offsetParent;     }     return tmp; } function getOffsetLeft(obj){
      var tmp = obj.offsetLeft;     var val = obj.offsetParent;     while(val != null){
          tmp += val.offsetLeft;         val = val.offsetParent;     }     return tmp; }    
    
 
    
 
    
 
    
  
     
      这里是图片，因为我用div边框1px，所以两个div会有2px的位置偏移，你可以自己调整