打开/关闭可鼠标拖动的层

话不多说，先上演示：

再上主要JS代码：

<script type="text/javascript">
 var prox;
 var proy;
 var proxc;
 var proyc;
 function show(id){/*--打开--*/
  clearInterval(prox);
  clearInterval(proy);
  clearInterval(proxc);
  clearInterval(proyc);
  var o = document.getElementById(id);
  o.style.display = "block";
  o.style.width = "1px";
  o.style.height = "1px";
  prox = setInterval(function(){openx(o,500)},10);
 }
 function openx(o,x){/*--打开x--*/
  var cx = parseInt(o.style.width);
  if(cx < x){
   o.style.width = (cx + Math.ceil((x-cx)/5)) +"px";
  }else{
   clearInterval(prox);
   proy = setInterval(function(){openy(o,200)},10);
  }
 }
 function openy(o,y){/*--打开y--*/
  var cy = parseInt(o.style.height);
  if(cy < y){
   o.style.height = (cy + Math.ceil((y-cy)/5)) +"px";
  }else{
   clearInterval(proy);
  }
 }
 function closeed(id){/*--关闭--*/
  clearInterval(prox);
  clearInterval(proy);
  clearInterval(proxc);
  clearInterval(proyc);
  var o = document.getElementById(id);
  if(o.style.display == "block"){
   proyc = setInterval(function(){closey(o)},10);
  }
 }
 function closey(o){/*--打开y--*/
  var cy = parseInt(o.style.height);
  if(cy > 0){
   o.style.height = (cy - Math.ceil(cy/5)) +"px";
  }else{
   clearInterval(proyc);
   proxc = setInterval(function(){closex(o)},10);
  }
 }
 function closex(o){/*--打开x--*/
  var cx = parseInt(o.style.width);
  if(cx > 0){
   o.style.width = (cx - Math.ceil(cx/5)) +"px";
  }else{
   clearInterval(proxc);
   o.style.display = "none";
  }
 }
 
 /*-------------------------鼠标拖动---------------------*/
 var od = document.getElementById("fd");
 var dx,dy,mx,my,mouseD;
 var odrag;
 var isIE = document.all ? true : false;
 document.onmousedown = function(e){
  var e = e ? e : event;
  if(e.button == (document.all ? 1 : 0)){
   mouseD = true;
  }
 }
 document.onmouseup = function(){
  mouseD = false;
  odrag = "";
  if(isIE){
   od.releaseCapture();
   od.filters.alpha.opacity = 100;
  }else{
   window.releaseEvents(od.MOUSEMOVE);
   od.style.opacity = 1;
  }
 }
 
 //function readyMove(e){
 od.onmousedown = function(e){
  odrag = this;
  var e = e ? e : event;
  if(e.button == (document.all ? 1 : 0)){
   mx = e.clientX;
   my = e.clientY;
   od.style.left = od.offsetLeft + "px";
   od.style.top = od.offsetTop + "px";
   if(isIE){
    od.setCapture();
    od.filters.alpha.opacity = 50;
   }else{
    window.captureEvents(Event.MOUSEMOVE);
    od.style.opacity = 0.5;
   }
   //alert(mx);
   //alert(my);
  }
 }
 document.onmousemove = function(e){
  var e = e ? e : event;
  //alert(mrx);
  //alert(e.button);
  if(mouseD==true && odrag){
   var mrx = e.clientX - mx;
   var mry = e.clientY - my;
   od.style.left = parseInt(od.style.left) +mrx + "px";
   od.style.top = parseInt(od.style.top) + mry + "px";
   mx = e.clientX;
   my = e.clientY;
  }
 }
</script>