window.onload = function() {
  document.getElementById("changeButton0").onmouseover = function() {
    map.change(["images/map_00.gif"]);
  }
  document.getElementById("changeButton1").onmouseover = function() {
    map.change(["images/map_01.gif"]);
  }
  document.getElementById("changeButton2").onmouseover = function() {
    map.change(["images/map_02.gif"]);
  }
  document.getElementById("changeButton3").onmouseover = function() {
    map.change(["images/map_03.gif"]);
  }
  document.getElementById("changeButton4").onmouseover = function() {
    map.change(["images/map_04.gif"]);
  }
  document.getElementById("changeButton5").onmouseover = function() {
    map.change(["images/map_05.gif"]);
  }
  document.getElementById("changeButton6").onmouseover = function() {
    map.change(["images/map_06.gif"]);
  }
  document.getElementById("changeButton7").onmouseover = function() {
    map.change(["images/map_07.gif"]);
  }
  document.getElementById("changeButton8").onmouseover = function() {
    map.change(["images/map_08.gif"]);
  }
}
var map = {
  change : function(imageArray){
    var imgTag = document.getElementById("shopArea").getElementsByTagName("img");
    for (var i=0; i<imgTag.length; i++) {
      imgTag[i].src = imageArray[i];
    }
  }
}