var Sys = {};
var ua = navigator.userAgent.toLowerCase();
if (window.ActiveXObject)
    Sys.ie = ua.match(/msie ([\d.]+)/)[1]
else if (document.getBoxObjectFor)
    Sys.firefox = ua.match(/firefox\/([\d.]+)/)[1]
else if (window.MessageEvent && !document.getBoxObjectFor)
    Sys.chrome = ua.match(/chrome\/([\d.]+)/)[1]
else if (window.opera)
    Sys.opera = ua.match(/opera.([\d.]+)/)[1]
else if (window.openDatabase)
    Sys.safari = ua.match(/version\/([\d.]+)/)[1];

var currslid = 0;
var slidint;
function setfoc(id) {
    var focpic = document.getElementById("focpic");
    document.getElementById("focpic").src = picarry[id];
    document.getElementById("foclnk").href = lnkarry[id];
    document.getElementById("foctitle").innerHTML = '<a href="' + lnkarry[id] + '" target="_blank">' + ttlarry[id] + '</a>';

  	currslid = id;
	for(i=0;i<4;i++){
		document.getElementById("tmb"+i).className = "thumb_off";
	};
	document.getElementById("tmb"+id).className ="thumb_on";
	focpic.style.visibility = "hidden";
	//现在只做ie浏览器的判断，主要是为了让图片出来有炫的效果。i6或更低版本和别的浏览器没有这个特性故做判断
	if (Sys.ie == 7 || Sys.ie == 8){
	    focpic.filters[0].Apply(); 
	    }	
	if (focpic.style.visibility == "visible") {
		focpic.style.visibility = "hidden";
		focpic.filters.revealTrans.transition=23;
	}
	else {
	    focpic.style.visibility = "visible";
	    if (Sys.ie == 7 || Sys.ie == 8) {
	        focpic.filters[0].transition = 23;
	    }
}
    if (Sys.ie == 7 || Sys.ie == 8) {
        focpic.filters[0].Play();
    }
	stopit();
}

function playnext(){
	if(currslid==3){
		currslid = 0;
	}
	else{
		currslid++;
	};
	setfoc(currslid);
	playit();
}
function playit(){
	slidint = setTimeout(playnext,4500);
}
function stopit(){
	clearTimeout(slidint);
	}
window.onload = function(){
	playit();
}