/*@author xiaojue*/
//JS翻页类
var Npage=function(pageparent,putwhere,pagechild,size){
	//类初始化
	Npage.num=1;
	Npage.s=document.getElementById(pageparent);
	Npage.p=document.getElementById(putwhere);
	Npage.d=document.getElementById(pageparent).getElementsByTagName(pagechild);
	Npage.size=size;
	//跳转
	Npage.pagegoto = function(i){
	Npage.num=i;
	pageup();
	};
	//判断参数是否合法
	if(Npage.s==null || Npage.p==null || Npage.d==null || isNaN(Npage.size)) return;
	
	//分页
	var nowpage=function(){
		var nowpagehtml=[];
		for(i=1;i<=zsize();i++){
			nowpagehtml.push("<a href='#"+i+"' onclick='Npage.pagegoto("+i+")'>"+i+"</a>");
		}
		nowpagehtml=nowpagehtml.join(" ");
		return nowpagehtml;
	}
	//输出
	Npage.p.innerHTML="每页共"+Npage.size+"条";
	Npage.p.innerHTML+=" <a href='#prev' class='Nprev'>上一页</a>";
	Npage.p.innerHTML+=nowpage();
	Npage.p.innerHTML+=" <a href='#next' class='Nnext'>下一页</a>";
	Npage.p.innerHTML+=" 共有"+zsize()+"页";
	
	//上下分页
	var Na=Npage.p.getElementsByTagName("a");
	for(i=0;i<Na.length;i++){
		if(Na[i].className!="Nprev") continue;
			Na[i].onclick=Nprevaction;
	}
	for(i=0;i<Na.length;i++){
		if(Na[i].className!="Nnext") continue;
			Na[i].onclick=Nnextaction;
	}
	//
	pageup();
};
//显示条数
var pageup = function(){
	for (i = 0; i < Npage.d.length; i++) {
				Npage.d[i].style.display = "none";
			}
	for (j = 0; j < Npage.d.length; j++) {
		if (j >= Npage.num*Npage.size || j < (Npage.num-1)*Npage.size) continue;
		Npage.d[j].style.display = "block";
	}
}
//获得总页数
var zsize=function(){return Math.ceil(Npage.d.length/Npage.size);} 
//分页
var Nprevaction=function(){
	if(Npage.num==1){alert("没有上一页了");return}
	Npage.num=Npage.num-1;
	pageup();
	}
var Nnextaction=function(){
	if(Npage.num==zsize()){alert("没有下一页了");return}
	Npage.num=Npage.num+1;
	pageup();
	}