/**
 * Gets Key/Values from a custom list.
 * @param listScriptId List Script Id, such as 'customlist_size'
 * @returns {Object} {'1':'Small','2':'Medium'}
 */
function getListItems(listScriptId) {
    var listItems = {};

    search.create({
        type: listScriptId,
        columns: ['name']
    }).run().each(function (result) {
        listItems[result.id] = result.getValue({ name: 'name' });
        return true;
    });

    return listItems;
}