// AJAX 宣告
  var xmlHttp;

  function createXMLHttpRequest() {
     if (window.ActiveXObject) {
              xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
     } 
     else if (window.XMLHttpRequest) {
              xmlHttp = new XMLHttpRequest();
    }
  } 
  
function J_swapImgRestore(id){
   document.getElementById(id).src = "images/btn_download.jpg";
}
function J_swapImage(id){
   document.getElementById(id).src = "images/btn_download_a.jpg";
}