var serviceObj = null;
 
window.onload = init;
 
// Initializes the widget
function init() {
    // Obtain the service object
    try {
        serviceObj = device.getServiceObject("Service.Calendar",
            "IDataSource");
    } catch (ex) {
        alert("Service object cannot be found.");
        return;
    }
 
    listCalendars(); 
}
 
function listCalendars() {
    try {
        var filter = new Object();
        // Not using the default calendar
        filter.DefaultCalendar = false;
 
        // Criteria for fetching calendars
        var criteria = new Object();
        criteria.Type = "Calendar";
        criteria.Filter = filter;
 
        // Get the list of calendars
        result = serviceObj.IDataSource.GetList(criteria);
        if (result.ErrorCode == 0) {
            showCalendars(result.ReturnValue);
        } else {
            alert("Error in getting calendars");
        }
    } catch( exception ) {
        alert("initialize error: " + exception);
    }
}
 
function showCalendars(iterator) {
    var calendarList = document.getElementById("calendarList");
 
    // Empty the calendar list
    while (calendarList.length != 0) {
        calendarList.remove(0);
    }
 
    // Set the pointer to the first element
    iterator.reset();
 
    var item;
    while ((item = iterator.getNext()) != undefined) {
        var node = document.createElement("option");
        node.value = item;
        node.appendChild(document.createTextNode(item));
        calendarList.appendChild(node);
    }
}