scoped_class_override.js

var Something = function(arg){
	console.log(['something:', arg]);
};

var Weird = function(fn){
	
	this.Something = function(arg){
		console.log(['something weird:', arg]);
	};
	
	if(fn && typeof fn == 'function'){
		return fn.call(this);
	}
};

new Something('test outside');

new Weird(function(){with(this)
	
	new Something('test inside');
	
});