function $A(iterable) { 
        var results = []; 
        for (var i = 0; i < iterable.length; i++)results.push(iterable[i]); 
        return results; 
    } 
    Function.prototype.bind = function() { 
        var __method = this, args = $A(arguments), object = args.shift(); 
        return function() { 
            return __method.apply(object, args.concat($A(arguments))); 
        } 
    } 
        var imgs = [ 
            {max:'./images/roll-1-1.jpg', min:'./images/roll-1-0.jpg', url:'./products/LED_bulbs.html', title:'LED lightbulbs', con:'Let the LED lightbulbs to replace fluorescent lamp bulbs.'}, 
            {max:'./images/roll-2-1.jpg', min:'./images/roll-2-0.jpg', url:'./Know_How/why-should-you-consider-led-flashlights.html', title:'Why should you consider led flashlights?', con:'LED flashlights are the development of the bulb flashlights, and wil be more and more used.'}, 
            {max:'./images/roll-3-1.jpg', min:'./images/roll-3-0.jpg', url:'./news/China-New-Energy-Plan.html', title:'Chinas New Energy Plan ', con:'Chinese government is promoting a huge investment in the energy,the support plan would focus on nuclear power and renewable energy as wind and solar power.'}, 
            {max:'./images/roll-4-1.jpg', min:'./images/roll-4-0.jpg', url:'./Know_How/Follow-the-solar-brick-road.html', title:'Follow the solar brick road?', con:'Solar brick is the self-illuminating bricks that contain solar-powered LEDs.'}, 
			{max:'./images/roll-5-1.jpg', min:'./images/roll-5-0.jpg', url:'./products/LED_Floodlights-1.html', title:'15W LED floodlight', con:'High power LED floodlight.'}
            ]
           ; 
        function focus(){this.initialize.apply(this,arguments)} 
        focus.prototype = { 
            initialize: function(imgs, fc, tim, speed){ 
                this.imgs    = imgs; 
                this.tim    = tim*1000 || 2000; 
                this.speed    = speed || 0.3; 
                this.t        = null;        // 动作计时 
                this.tm        = null;        // 图片计时 
                this.tb        = null;        // 滑块儿计时 
                this.cur_i    = 0;        // 当前图片位置 
                this.move    = false;    // 是否在运动 
                this.tem    = 0;        // 临时数据 
                this.posTo    = 0;        // 滑块儿目的地 
                this.over    = 0; 
                var ds        = document.getElementById(fc).getElementsByTagName('div'); 
                var di        = ds[0]; 
                this.img_m    = document.createElement('img'); 
                this.img_m2 = this.img_m.cloneNode(true); 
                var dm        = ds[1]; 
                this.title    = ds[3]; 
                this.con    = ds[4]; 
                this.mask    = document.createElement('div'); 
                this.ul        = document.createElement('ul'); 
                this.lis    = []; 
                this.img_m.style.zIndex = 101; 
                this.img_m2.style.zIndex = 100; 
                di.appendChild(this.img_m); 
                di.appendChild(this.img_m2); 
                di = null; 
                dm.appendChild(this.mask); 
                dm.appendChild(this.ul); 
                dm = null; 
                this.img_cache(); 
                this.load(); 
            }, 
            img_cache: function(){ 
                var img = new Image(); 
                for(var i=0; i<this.imgs.length; i++)img.src = this.imgs[i].max; 
            }, 
            stop: function(){ 
                clearTimeout(this.t); 
                this.over = 1; 
            }, 
            start: function(){ 
                this.over = 0; 
                this.t = setTimeout(this.f_next.bind(this,null), this.tim); 
            }, 
            load: function(){ 
                var imgs             = this.imgs; 
                this.img_m.src         = imgs[0].max;   // 加载默认大图 
                this.title.innerHTML = '<a href="'+imgs[0].url+'">'+imgs[0].title+'</a>'; // 标题 
                this.con.innerHTML     = imgs[0].con;      //内容 
                var oThis          = this; 
                for(var i=0; i<imgs.length; i++){     //加载小图 
                    var li              = document.createElement('li'); 
                        li.onclick      = function(){ oThis.f_next.call(oThis,this.i); } 
                        li.innerHTML  = '<img src="'+imgs[i].min+'" alt="" />'; 
                        li.i          = i; 
                        this.lis.push(li); 
                        this.ul.appendChild(li); 
                } 
                var lis = this.ul.childNodes; 
                for(var i=0; i<lis.length; i++){ 
                    lis[i].onmouseover = function(){ this.style.border="1px solid #cc0000"; } 
                    lis[i].onmouseout = function(){ this.style.border="1px solid #0066cc"; } 
                } 
                this.t = setTimeout(this.f_next.bind(this,null), this.tim); 
                this.title.parentNode.onmouseover = this.stop.bind(this); 
                this.title.parentNode.onmouseout = this.start.bind(this); 
            }, 
            f_next: function(n){ 
                if(this.tb) clearInterval(this.tb); 
                if(this.t) clearTimeout(this.t); 
                if(this.tm) clearInterval(this.tm); 
                if(n)this.cur_i = n-1; 
                var top = 0; 
                if(n!=0 && this.imgs[this.cur_i+1]){ 
                    this.posTo = this.lis[this.cur_i+1].offsetTop; 
                    this.cur_i = this.cur_i+1; 
                }else{ 
                    this.posTo = this.lis[0].offsetTop; 
                    this.cur_i = 0; 
                } 
                this.tem = this.mask.offsetTop; 
                this.tem > this.posTo? top = 1 : top = 0; 
                this.tb = setInterval(this.moveTo.bind(this, top), 25); 
            }, 
            moveTo: function(top){ 
                if(!top){ 
                    if((this.tem+1.8)>=this.posTo+1){ 
                        this.mask.style.top = this.posTo+'px'; 
                        clearInterval(this.tb); 
                        this.img_swap(); 
                        return; 
                    } 
                    this.tem += (this.posTo-this.tem)*this.speed 
                }else{ 
                    if((this.tem-1.8)<=this.posTo-1){ 
                        this.mask.style.top = this.posTo+'px'; 
                        clearInterval(this.tb); 
                        this.img_swap(); 
                        return; 
                    } 
                    this.tem -= (this.tem-this.posTo)*this.speed; 
                } 
                this.mask.style.top = this.tem+'px'; 
            }, 
            img_swap: function(){ 
                var t, b; 
                if(this.img_m.style.zIndex>this.img_m2.style.zIndex){ 
                    t = this.img_m; 
                    b = this.img_m2; 
                }else{ 
                    t = this.img_m2; 
                    b = this.img_m; 
                } 
                this.title.innerHTML = '<a href="'+this.imgs[this.cur_i].url+'">'+this.imgs[this.cur_i].title+'</a>'; 
                this.con.innerHTML     = this.imgs[this.cur_i].con; 
                b.src                 = this.imgs[this.cur_i].max; 
                /MSIE/.test(navigator.userAgent) ? this.tem = t.style.filter ? t.style.filter.replace(/^.+=(\d+).+$/,'$1') : 100 : this.tem = t.style.opacity ? t.style.opacity*100 : 100; 
                this.tm                 = setInterval(this.img_hid.bind(this, t, b), 25); 
            }, 
            img_hid: function(t,b){ 
                this.tem -= 5; 
                if(/MSIE/.test(navigator.userAgent)) 
                    t.style.filter = 'alpha(opacity='+this.tem+')'; 
                else 
                    t.style.opacity = this.tem/100; 
                if(this.tem <=0){ 
                    clearInterval(this.tm); 
                    var tz           = t.style.zIndex; 
                    var bz           = b.style.zIndex; 
                    t.style.zIndex = bz 
                    b.style.zIndex = tz; 
                    if(/MSIE/.test(navigator.userAgent)) 
                        t.style.filter = 'alpha(opacity=100)'; 
                    else 
                        t.style.opacity = 1; 
                    if(this.over) return; 
                    this.t = setTimeout(this.f_next.bind(this, null), this.tim); // 继续循环 
                } 
            } 
        } 
        window.onload = function(){ 
            new focus(imgs,'focus_m'); 
        }