Function deferring for javascript

defer.js

Function.prototype.defer = function(thisObj, parameters){
  if (typeof parameters == "undefined")
    parameters = [];

  if (typeof window.deferredActionsList === "undefined")
    window.deferredActionsList = [];

  if (typeof window.__deferredActionsRunner === "undefined")
    window.__deferredActionsRunner = setTimeout(function(){
      for(var key in window.deferredActionsList){
        obj = window.deferredActionsList[key]
        obj.action.apply(obj.thisObj, obj.parameters);
      }
    }, 0);

  window.deferredActionsList.unshift({action: this, thisObj: thisObj, parameters: parameters});
}