define(['dojo/_base/connect','dojo/_base/xhr','dojo/_base/Deferred','dojo/hash'],function(connect,xhr,Deferred,hash){
    return new (function() {
        var self = this;
        var current = "";
            
        function init() {
            connect.subscribe('/dojo/hashchange', function(){
                var url = hash();
                self.goTo(url);
            });
        }

        self.initial = function(location) {
            if ( current ) {
                self.goTo(location);
            }
            var url = hash();
            self.goTo(url || location);
        }
            
        self.goTo = function(location) {
            var contentPane = dijit.byId('content');
            var d = new Deferred();
            if ( current == location ) {
                d.resolve();
                return d.promise;
            }

            current = location;
            hash(location);
            xhr.get({
                url: 'pages/'+location+'/'+location+'.html'
            })
            .then(function(content){
                contentPane.set('content',content);
                d.resolve();
            },function(){
                contentPane.set('content',"Page "+location+" not found.");
                d.reject();
            });
            return d.promise;
        }
            
        init();
    })();
});