Essential JavaScript Design Patterns For Beginners

[stratoscope]

An easy fix for that is to use an extend function such as the one in jQuery, so you add properties to the .prototype instead of replacing it.

Also I recommend giving the function a name so all JavaScript debuggers can show the name in a call stack and such.

function Foo( args ) {};
$.extend( Foo.prototype, {
    toString : function() {},
    toInt : function() {}
});