function getstyle(obj,name)
{
	if(obj.currentstyle)
	{
		return obj.currentstyle[name]
	}
	else
	{
		return getcomputedstyle(obj,false)[name]
	}
}

function getbyclass(oparent,nclass)
{
	var ele = oparent.getelementsbytagname('*');
	var arrent  = [];
	for(var i=0; i<ele.length; i++)
	{
		if(ele[i].classname == nclass)
		{
			arrent.push(ele[i]);
		}
	}
	return arrent;
}

function startmove(obj,att,add)
{
	clearinterval(obj.timer)
	obj.timer = setinterval(function(){
	   var cutt = 0 ;
	   if(att=='opacity')
	   {
		   cutt = math.round(parsefloat(getstyle(obj,att)));
	   }
	   else
	   {
		   cutt = math.round(parseint(getstyle(obj,att)));
	   }
	   var speed = (add-cutt)/4;
	   speed = speed>0?math.ceil(speed):math.floor(speed);
	   if(cutt==add)
	   {
		   clearinterval(obj.timer)
	   }
	   else
	   {
		   if(att=='opacity')
		   {
			   obj.style.opacity = (cutt+speed)/100;
			   obj.style.filter = 'alpha(opacity:'+(cutt+speed)+')';
		   }
		   else
		   {
			   obj.style[att] = cutt+speed+'px';
		   }
	   }
	   
	},30)
}

  window.onload = function()
  {
	  var odiv = document.getelementbyid('playbox');
	  var opre = getbyclass(odiv,'pre')[0];
	  var onext = getbyclass(odiv,'next')[0];
	  var oulbig = getbyclass(odiv,'oulplay')[0];
	  var abigli = oulbig.getelementsbytagname('li');
	  var odivsmall = getbyclass(odiv,'smalltitle')[0]
	  var alismall = odivsmall.getelementsbytagname('li');
	  
	  function tab()
	  {
	     for(var i=0; i<alismall.length; i++)
	     {
		    alismall[i].classname = '';
	     }
	     alismall[now].classname = 'thistitle'
	     startmove(oulbig,'left',-(now*abigli[0].offsetwidth))
	  }
	  var now = 0;
	  for(var i=0; i<alismall.length; i++)
	  {
		  alismall[i].index = i;
		  alismall[i].onclick = function()
		  {
			  now = this.index;
			  tab();
		  }
	 }
	  opre.onclick = function()
	  {
		  now--
		  if(now ==-1)
		  {
			  now = abigli.length;
		  }
		   tab();
	  }
	   onext.onclick = function()
	  {
		   now++
		  if(now ==abigli.length)
		  {
			  now = 0;
		  }
		  tab();
	  }
	  var timer = setinterval(onext.onclick,3000) //�������ʱ������
	  odiv.onmouseover = function()
	  {
		  clearinterval(timer)
	  }
	   odiv.onmouseout = function()
	  {
		  timer = setinterval(onext.onclick,3000) //�������ʱ������
	  }
  }