//索引
//大小
//ID前缀 
//tag_N_0(切换导航命名) | tag_C_0(切换内容命名)
function switchTab(index,size,tag){
	for(var i = 0;i<size;i++){
		document.getElementById(tag+"_N_"+i).className="";
		document.getElementById(tag+"_C_"+i).style.display="none";
	}
	document.getElementById(tag+"_N_"+index).className="on";
	document.getElementById(tag+"_C_"+index).style.display="block";
}
function buildsubNav(menuids){
	for (var i=0; i<menuids.length; i++){
		var ultags=document.getElementById(menuids[i]).getElementsByTagName("ul");
		for (var t=0; t<ultags.length; t++){
			ultags[t].parentNode.getElementsByTagName("a")[0].className="sub";
			ultags[t].parentNode.onmouseover=function(){
				this.getElementsByTagName("ul")[0].style.display="block";
			}
			ultags[t].parentNode.onmouseout=function(){
				this.getElementsByTagName("ul")[0].style.display="none";
			}
		}
  }
}
$(function(){
	buildsubNav(["nav_L1"]);
	var bannerI = 0;
	var bannerS = 2;
	$("#banner_N_U").click(function(){
		bannerI--;
		if(bannerI<0)bannerI=0;
		switchTab(bannerI,2,"banner");
	});
	$("#banner_N_D").click(function(){
		bannerI++;
		if(bannerI>(bannerS-1))bannerI=bannerS-1;
		switchTab(bannerI,2,"banner");});
	$("#banner_N_0").click(function(){switchTab(0,bannerS,"banner");});
	$("#banner_N_1").click(function(){switchTab(1,bannerS,"banner");});
	$("#banner_N_1").click(function(){switchTab(1,bannerS,"banner");});
})
function showson(id){
	$("#"+id).toggle();
}