var who;
function showMenu(num){
var bj=document.getElementById("bj")
	if(num==0){
		bj.style.backgroundPosition="0 0";
		who	.style.display="none";
	}else if(num>=1){
		bj.style.backgroundPosition="0 -"+(49*num);	
		document.getElementById("menu"+num).style.display="block";
		who=document.getElementById("menu"+num)
	}
}

function Show(obj,num,o){
	
	if(num){
		bj.style.backgroundPosition="0 -"+(49*num);	
	}

	if(o==null){
	obj.style.display="block";
	}else{
	document.getElementById("bj").style.backgroundPosition="0 0";
	obj.style.display="none";	
	}
	
}