text: var flag=false//全局变量
  function show_menu(){
  		var title1=document.getElementById("title");
  		if(flag){
  			title1.style.display="none";
  			flag=false;
  		}else{
  			title1.style.display="block";
  			flag=true;
  		}
  }
  function show_menu1(){
  		var title1=document.getElementById("title");
  			title1.style.display="none";
  			flag=false;
  }
  