auto_click.js

AutoClick = {};
AutoClick.keydown = function(k) {
  var oEvent = document.createEvent('KeyboardEvent');

  Object.defineProperty(oEvent, 'keyCode', {
    get : function() {
      return this.keyCodeVal;
    }
  });     
  Object.defineProperty(oEvent, 'which', {
    get : function() {
      return this.keyCodeVal;
    }
  });     

  if (oEvent.initKeyboardEvent) {
    oEvent.initKeyboardEvent("keydown", true, true, document.defaultView, false, false, false, false, k, k);
  } else {
    oEvent.initKeyEvent("keydown", true, true, document.defaultView, false, false, false, false, k, 0);
  }

  oEvent.keyCodeVal = k;

  if (oEvent.keyCode !== k) {
    alert("keyCode mismatch " + oEvent.keyCode + "(" + oEvent.which + ")");
  }

  document.dispatchEvent(oEvent);
}