var agent = navigator.userAgent;

String.prototype.inc = function(k1, k2)
{
	return k2 == null ? this.indexOf(k1) > -1 ? true : false : (k2 + this + k2) .indexOf(k2 + k1 + k2) > -1 ? true : false;
};

var is_Opr = agent.inc("Opera");
var is_IE = agent.inc("IE") && !is_Opr;

var img_list = new Array();
var num_of_img;
var t_img;
var t_link;

var status = 1;
var img_index = 0;
var timerID = null;
var t_name;
var bt_run = "images/bt_run.gif";
var bt_stop = "images/bt_stop.gif";
var image = new Array();

//根据ID取对象
function oo(obj)
{
	return document.getElementById(obj);
}

function isIE()
{	
	return is_IE;
}

function preLoad(p_img_list, p_id_img, p_id_link, p_id_name)
{	
	img_list = p_img_list;
	num_of_img = img_list.length;

	t_img = oo(p_id_img);
	if(t_img == null) return;
	
	t_link	 = oo(p_id_link);
	t_name	 = p_id_name;

	for(var i = 0; i < num_of_img; i++)
	{
   		image[i] = new Image();
		image[i].src = img_list[i];
	}
}

function play()
{
	nextImg(1);
	if(num_of_img == 1) return;
	timerID = setTimeout("play();", 4000);
}

function nextImg(next)
{
	if(t_img == null) return;
	
	if(isIE()) //ie判断
	{
		t_img.filters.revealTrans.transition=23;
		t_img.filters[0].Apply();
	}

	img_index = (img_index+next) % num_of_img;
	if(img_index < 0) 
	{
		img_index = num_of_img - 1;
	}
	t_img.src = image[img_index].src;//img_list[img_index][0];
	
	//if(t_name != null)
	//{
	//	show_msg(t_name,img_list[img_index][1]);
	//}

	if(isIE())
	{	
		t_img.filters[0].Play();
	}
}

function playOrPause(b_id)
{
	if(status == 1)
	{
		if(timerID!=null) clearTimeout(timerID);
		oo(b_id).src = bt_run;
		oo(b_id).title = "继续";
		status = 0;
	}
	else if(status == 0)
	{
		timerID = setTimeout("play();", 4000);
		oo(b_id).src = bt_stop;
		oo(b_id).title = "暂停";
		status = 1;
	}
}