Sorting an Object by it's keys alphabetically

sortObject.js

var params = {
    method: 'artist.getInfo',
    api_key: '9bd9ee',
    user_id: '3016',
    format: 'json',
    nojsoncallback: 1,
    auth_token: '7215'
};

function sortObject(o) {
    var sorted = {},
    key, a = [];

    for (key in o) {
    	if (o.hasOwnProperty(key)) {
    		a.push(key);
    	}
    }

    a.sort();

    for (key = 0; key < a.length; key++) {
    	sorted[a[key]] = o[a[key]];
    }
    return sorted;
}

console.log(sortObject(params));