auto=null;
timer=null;
var focus=new function();
focus.prototype={
	init:function(){

		this.atime=this.atime || 10;

		this.stime=this.stime || 5000;

		this.oimg=document.getelementbyid('focus_m').getelementsbytagname("ul")[0];
		this.oimgli=this.oimg.getelementsbytagname("li");

		this.ol=document.getelementbyid('focus_l');
		this.or=document.getelementbyid('focus_r');

		this.createtextdom();

		this.target=0;

		this.automove();

		this.oaction();
	},
	createtextdom:function(){
		var that=this;

		this.otext=document.createelement("div");
		this.otext.classname="focus_s";
		var ul=document.createelement('ul');
		var frag=document.createdocumentfragment();
		for (var i=0;i<this.oimgli.length;i++) {
			var li=document.createelement("li");
			li.innerhtml='<b></b>';
			if (i==0) {
				li.classname="active";
			};
			frag.appendchild(li);
		};
		ul.appendchild(frag);
		this.otext.appendchild(ul);
		this.o.insertbefore(this.otext,this.o.firstchild);

		this.otextli=this.otext.getelementsbytagname("li");		
	},
	automove:function(){
		var that = this;   
		auto=setinterval(function(){that.gonext()},that.stime);
	},
	gonext:function() {
		this.target=this.nowindex();
		this.target==this.otextli.length-1 ? this.target=0:this.target++;
		this.astep=(this.target-this.nowindex())*this.step;
		this.removeclassname();
		this.otextli[this.target].classname="active";
		this.startmove();
	},
	goprev:function() {
		this.target=this.nowindex();
		this.target==0 ? this.target=this.otextli.length-1 : this.target--;
		this.astep=(this.target-this.nowindex())*this.step;
		this.removeclassname();
		this.otextli[this.target].classname="active";
		this.startmove();
	},
	startmove:function (){
		var that=this;
		var t=0;
		this.timer='';
		function set(){
			if (t>100) {
				clearinterval(that.timer);
			}else {
				for (var i=0;i<that.oimgli.length;i++) {
					that.oimgli[i].style.display='none';
				};
				that.oimgli[that.target].style.display='block';
				that.setopacity(that.oimg,t);
				t+=5;
			};
		};
		timer=setinterval(set,that.atime);
	},
	setopacity:function(elem,level){
		if(elem.filters){
			elem.style.filter = 'alpha(opacity=' + level + ')';
			elem.style.zoom = 1;
		} else {
			elem.style.opacity = level / 100;
		};
	},
	nowindex:function(){
		for (var i=0;i<this.otextli.length;i++) {
			if (this.otextli[i].classname=='active') {
				return i;
				break;
			}
		};
	},
	oaction:function(){
		var that=this;
		for (var i=0;i<this.otextli.length;i++) {
			this.otextli[i].index=i;
			this.otextli[i].onclick=function(){
				clearinterval(auto);
				clearinterval(timer);
				that.setopacity(that.oimg,100);
				that.target=this.index;
				that.removeclassname();
				this.classname='active';
				that.startmove();
			}
		};
		mouseenter (that.o,'mouseleave',function(e){
				clearinterval(auto);
				that.automove();
			}
		);
		this.ol.onclick=function(){
			that.goprev();
		};
		this.or.onclick=function(){
			that.gonext();
		};
	},
	removeclassname:function(){
		for (var i=0;i<this.otextli.length;i++) {
			this.otextli[i].classname=""
		};
	}
};
var focusrun=new focus();
focusrun.o=document.getelementbyid("focus");
function mouseenter(ele,type,func){
	if(window.document.all)	
		ele.attachevent('on'+type,func);
	else{//ff
		if(type==='mouseenter')
			ele.addeventlistener('mouseover',this.withoutchildfunction(func),false);
		else if(type==='mouseleave')
			ele.addeventlistener('mouseout',this.withoutchildfunction(func),false);
		else
			ele.addeventlistener(type,func,false);		
	};
};
function withoutchildfunction(func){
	return function(e){
		var parent=e.relatedtarget;
		while(parent!=this&&parent){
			try{
				parent=parent.parentnode;}
			catch(e){
				break;
			}
		}
		if(parent!=this)
		func(e);
	};
};

window.onload=function(){
	focusrun.init();
};