鼠标拖动，放开时坐标有关问题.

鼠标拖动，放开时坐标问题...
var div_img = document.getElementById("img");
   
  div_img.onmousedown = startdarg;
  div_img.onmouseup = stopdarg;

function startdarg(event)
{
  if (!event)
  {
  event = window.event;
  x=event.offsetX;
  y =event.offsetY;
  alert(x + " " + y);
   
  }

}

function stopdarg(event)
{
  if (!event)
  {
  //alert("haha");
  event = window.event;
  var a = event.offsetX;
  var b = event.offsetY;
   
  alert(a + " " + b);
   
  }
   
}

这样子的话，鼠标左键按下去，是可以得到正确的值，但是一直按着鼠标进行拖动，放开鼠标时，根本就不会执行stopdrag，要怎么才能得到鼠标放开时的坐标呢？？


[解决办法]
没有执行是因为你根本没有触发stopdrag,因为你startdrag的时候alert了一下,这个时候已经blur了,松开鼠标触发不到事件了

JScript code

<script>var div_img = document.getElementById("img");                  div_img.onmousedown = startdarg;         div_img.onmouseup = stopdarg; function startdarg(event) {         if (!event)         {         event = window.event;          x=event.offsetX;           y =event.offsetY;         //alert(x + "  " + y);           self.status=x+":"+y;               } } function stopdarg(event) {         if (!event)         {                 //alert("haha");                 event = window.event;                 var a = event.offsetX;                 var b = event.offsetY;                                  //alert(a + "  " + b);                 self.status=a+":"+b;                         }          }</script>