function changeMc(a,b,c,d,e){//增删个数，下面做相应调整
document.getElementById(a).style.display = "block"
document.getElementById(b).style.display = "none"
document.getElementById(c).style.display = "none"
document.getElementById(d).style.display = "none"
document.getElementById(e).style.display = "none"
}


function doClick(o){
	// o.className="cd1_ov";
	 //var j;
	 var id;
	 var e;
	 for(var i=1;i<=5;i++){
	   id ="nav"+i;
	   j = document.getElementById(id);
	   e = document.getElementById("sub"+i);
	   if(id != o.id){
	   	 //j.className="cd2";
	   	 e.style.display = "none";
	   }else{
			e.style.display = "block";
	   }
	 }
	 }