Accessing the QueryString in JavaScript

Yesterday I needed to access a querystring parameter, from JavaScript. There is no in-built object or property but there are plenty of examples of how to do this. However, I've written a neat self executing function (Figure 1) that gets the key/value pairs, for each querystring parameter, and creates a querystring property on the window.location object.

(function(location){
 var querystring = {};
    location.search.replace(/([^?=&]+)(=([^&]*))?/g, function($0, $1, $2, $3){
        querystring[$1] = $3;
    });
    location.querystring = querystring;
})(window.location);

Figure 1