Json Angular 无法重复订购工作

我用orderBytry 了很多ng repeat的例子，但我无法让我的json使用它.

<div ng-app>
    <script type="text/javascript" src="http://code.angularjs.org/1.0.1/angular-1.0.1.js"></script>
    <div ng:controller="Main">
        <div ng-repeat="release in releases| orderBy:'environment_id'">      
            {{release.environment_id}}
        </div>
    </div>
</div>

还有JSON

function Main($scope) {
$scope.releases = {
    "tvl-c-wbap001 + tvl-webapp": {
        "timestamp": " 05:05:53 PM ",
        "environment_id": "CERT5",
        "release_header": "Projects/Dev",
        "date": "19 Oct",
        "release": "12.11.91-1"
    },
    "tvl-c-wbap401 + tvl-webapp": {
        "timestamp": " 10:07:25 AM ",
        "environment_id": "CERT4",
        "release_header": "Future Release",
        "date": "15 Oct",
        "release": "485-1"
    },
    "tvl-c-wbap301 + tvl-webapp": {
        "timestamp": " 07:59:48 AM ",
        "environment_id": "CERT3",
        "release_header": "Next Release",
        "date": "15 Oct",
        "release": "485-1"
    },
    "tvl-c-wbap201 + tvl-webapp": {
        "timestamp": " 03:34:07 AM ",
        "environment_id": "CERT2",
        "release_header": "Next Changes",
        "date": "15 Oct",
        "release": "13.12.3-1"
    },
    "tvl-c-wbap101 + tvl-webapp": {
        "timestamp": " 12:44:23 AM ",
        "environment_id": "CERT1",
        "release_header": "Production Mirror",
        "date": "15 Oct",
        "release": "13.11.309-1"
    },
    "tvl-s-wbap002 + tvl-webapp": {
        "timestamp": " 12:43:23 AM ",
        "environment_id": "Stage2",
        "date": "15 Oct",
        "release": "13.11.310-1"
    },
    "tvl-s-wbap001 + tvl-webapp": {
        "timestamp": " 11:07:38 AM ",
        "environment_id": "Stage1",
        "release_header": "Production Mirror",
        "date": "11 Oct",
        "release": "13.11.310-1"
    },
    "tvl-p-wbap001 + tvl-webapp": {
        "timestamp": " 11:39:25 PM ",
        "environment_id": "Production",
        "release_header": "Pilots",
        "date": "14 Oct",
        "release": "13.11.310-1"
    },
    "tvl-p-wbap100 + tvl-webapp": {
        "timestamp": " 03:27:53 AM ",
        "environment_id": "Production",
        "release_header": "Non Pilots",
        "date": "11 Oct",
        "release": "13.11.309-1"
    }
}

It doesn't matter what I write, I always get the same order, or I may say, no order at all.