Override function (e.g. “alert”) and call the original function?

Question

I would like to override a Javascript built-in function with a new version that calls the original (similarly to overriding a method on a class with a version that calls

Answer 1

How to do simple classical inheritance in Javascript:

SuperClass.call(this) // inherit from SuperClass (multiple inheritance yes)

How to override functions:

this.myFunction = this.myFunction.override(
                    function(){
                      this.superFunction(); // call the overridden function
                    }
                  );

The override function is created like this:

Function.prototype.override = function(func)
{
 var superFunction = this;
 return function() 
 {
  this.superFunction = superFunction;
  return func.apply(this,arguments);
 };
};

Works with multiple arguments.
Fails when trying to override undefined or nonfunctions.
Makes "superFunction" a "reserved" word :-)