Right now we use codemirror's JavaScript mode on the website but there's a JSX mode now so we should start using that instead.

if (ie && (!cm.state.draggingText || +new Date - lastDrop < 100)) { e_stop(e); return; }
    if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e)) return;
    var txt = cm.getSelection();
    e.dataTransfer.setData("Text", txt);
    
    
    if (e.dataTransfer.setDragImage && !safari) {
      var img = elt("img", null, null, "position: fixed; left: 0; top: 0;");
      img.src = "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==";
      if (opera) {
        img.width = img.height = 1;
        cm.display.wrapper.appendChild(img);
        
        img._top = img.offsetTop;
      }
      e.dataTransfer.setDragImage(img, 0, 0);
      if (opera) img.parentNode.removeChild(img);
    }
  }
  function setScrollTop(cm, val) {
    if (Math.abs(cm.doc.scrollTop - val) < 2) return;
    cm.doc.scrollTop = val;
    if (!gecko) updateDisplay(cm, [], val);
    if (cm.display.scroller.scrollTop != val) cm.display.scroller.scrollTop = val;
    if (cm.display.scrollbarV.scrollTop != val) cm.display.scrollbarV.scrollTop = val;
    if (gecko) updateDisplay(cm, []);
    startWorker(cm, 100);
  }
  function setScrollLeft(cm, val, isScroller) {