////PDFファイルを自動的に_blank
window.onload = function() {
 var elem = document.getElementsByTagName('a');
 for (var i = 0; i < elem.length; i++) {
  var str = elem[i].href;
  if(elem[i].href.match(/pdf$/i)){
   elem[i].target = "_blank";
  }
 }
}