var obj;
var offsetX;
var offsetY;

onload=function () {
   if (document.all) {
      objlist = document.getElementById('dragdrop');
   } else if (document.getElementsByTagName) {
      objlist = document.getElementById('dragdrop');
   } else {
      return;
   }
   if(!objlist){
      return;
   }
   objlist.onmousedown = onMouseDown;
   document.onmousemove = onMouseMove;
   document.onmouseup = onMouseUp;
}
function onMouseDown(e) {
   obj = this;
   if (document.all) {
      offsetX = window.event.offsetX + 2;
      offsetY = window.event.offsetY + 2;
   } else if (obj.getElementsByTagName) {
      offsetX = e.pageX - parseInt(obj.style.left);
      offsetY = e.pageY - parseInt(obj.style.top);
   }
   return false;
}
function onMouseMove(e) {
   if (!obj) {
      return true;
   }
   if (document.all) {
      obj.style.left = window.event.clientX - offsetX + document.body.scrollLeft;
      obj.style.top  = window.event.clientY - offsetY + document.body.scrollTop;
   } else if (obj.getElementsByTagName) {
      obj.style.left = e.pageX - offsetX;
      obj.style.top = e.pageY - offsetY;
   }
   return false;
}
function onMouseUp(e) {
   obj = null;
}