//图片切换
//sanda lwq

/*---------------------------------------------------------------------
	类定义
---------------------------------------------------------------------*/

function ImgSwitchClass(){   

//-----------------------私有属性-----------------------
var NowFrame = 1;
var MaxFrame = 3;
var SwitchTimer = false;
var ImgSwitchObj;//必须现在就定义，否则执行onClick="ImgSwitchObj.ManualSwitch(1)"时出错

//-----------------------私有方法-----------------------
//向右循环切换
function Next() {
	var page = (NowFrame==MaxFrame ? 1 : NowFrame + 1);
	//执行切换
	GetPage(page);
}

//手动切换
function ManualSwitch(page) {
	//停止定时
	StopSwitchTimer();
	if(NowFrame!=page)
	{
		GetPage(page);
	}
	//恢复定时
	StartSwitchTimer();
}

//按样式切换
function GetPage(page) {
	if (is_ie)
	{
		//决定向前或向后
		var obj_div_filter = $("isImgContainer").filters[0];
		if(page > NowFrame)
		{
			obj_div_filter.motion = "reverse";
		}
		else
		{
			obj_div_filter.motion = "forward";
		}	
		//执行切换
		$("isImgContainer").filters[0].Apply();
	}
	document.images['isImg'+page].style.display = "";
	document.images['isImg'+NowFrame].style.display = "none"; 
	if (is_ie)
	{
		$("isImgContainer").filters[0].Play(duration=1);
	}
	NowFrame = page;
	//设置isSwitcher的格式
	var obj=$("isSwitcher").getElementsByTagName("a");
	for (i=0;i<obj.length;i++)
	{
		obj[i].className="isF1";
	}
	obj[page-1].className="isF2";
}

//开始切换
function StartSwitchTimer() { 
	SwitchTimer = setInterval(Next, 4000);
}

//停止切换
function StopSwitchTimer() { 
	clearInterval(SwitchTimer);
}

//-----------------------公有-----------------------
//				( 从对象外部访问 )
this.StartSwitchTimer = StartSwitchTimer;
this.ManualSwitch = ManualSwitch;
}