img1=new Image();
img1.src ="images/menu_b_01.png";
img2=new Image();
img2.src ="images/menu_b_02.png";
img3=new Image();
img3.src ="images/menu_b_03.png";
img4=new Image();
img4.src ="images/menu_b_04.png";
img5=new Image();
img5.src ="images/menu_b_05.png";
img6=new Image();
img6.src ="images/menu_b_06.png";
img7=new Image();
img7.src ="images/menu_b_07.png";
img8=new Image();
img8.src ="images/menu_b_08.png";
img9=new Image();
img9.src ="images/menu_b_09.png";
img9=new Image();
img9.src ="images/menu_b_10.png";


function preLoad(){
  var imgCount = 9;//需要预先加载10张图片
  var images = new Array();
  for (var i=0;i<imgCount;i++){
    images[i] = new Image();
    images[i].src ="images/menu_b_0"+ (i+1) + ".png";
  }
}


// JavaScript Document
function menu_sub_in(id) {
//document.getElementById('menu_sub_travel').style.display = "block";
	document.getElementById(id).style.display = 'block';
	//menu_sub_travel.style.display = 'block';
} 
function menu_sub_out(id){ 
	//menu_sub_travel.style.display = 'none';
	document.getElementById(id).style.display = 'none';
}