function options(obj, selected) {
    var html = '';
    for (var key in obj) {
        html += '<option value="' + key + '" '
            + (key == selected ? 'selected="selected"' : '')
            + '>' + obj[key] + '</option>\n';
    }
    return html;
}
Generate options from `obj`.

@param {Object} obj
@param {String} selected
@return {String}