Edit in JSFiddle

var YourGlobal = {
	namespace: function(ns) {
		var parts = ns.split("."),
			object = this,
			i, len;

		for (i=0, len=parts.length; i < len; i++) {

			if (!object[parts[i]]) {
				object[parts[i]] = {};
			}

			object = object[parts[i]];
		}

		return object;
	}
};

YourGlobal.namespace("Books.MaintainableJavaScript");
YourGlobal.Books.MaintainableJavaScript.author = "Nicholas C. Zakas";