var menuImg0 = "images/menu1.gif" 
var menuImg1 = "images/menu2.gif" 
var menuImg2 = "images/menu3.gif" 
  function changeImgOver(imgName){
    imgName.src = menuImg1
    }

  function changeImgOut(imgName){
    imgName.src = menuImg0
    }
  
  function changeImgOutDl(imgName){
    imgName.src = menuImg2
    }