function Base()
{
}
Base.prototype.a = function()
{
alert('a in Base');
}
function Derived()
{
}
Derived.prototype = new Base();
Derived.prototype.base = new Base();
Derived.prototype.a = function()
{
alert('a in Derived');
}
var b = new Base();
b.a();
var c = new Derived();
c.a();
c.base.a();