IE Object.prototype.__defineGetter__.js

Object.prototype.__defineGetter__ = function(name, _fn)
{
  var self = this;
  var _wrapper = function()
  {
    return _fn.call(self); 
  };
  
  this[name] = 
  {
    valueOf: _wrapper,
    toString: _wrapper,
    jbGetter_: 1 // mark
  };
};

Object.prototype.__lookupGetter__ = function(name)
{
  if(this.hasOwnProperty(name) && this[name].hasOwnProperty('jbGetter_'))
    return this[name].valueOf;
};