to support user-intefaces with human-readable high-level elements and on the other hand, machine-originated users with low-level data. Most of the maintenance functions are synchronous, only one is asynchronous; hspsGetNextHeader(). Others functions are straightforward to use but hspsGetListHeaders(). This will be explained next; synchronous call hspsGetListHeaders() initiates the theme header listing by passing search mask to HSPS Theme Server's Maintenance Service. This search mask is called a query. It also passes a list object in where maintenance service should append theme-header objects (type of ChspsODT-class without DOM-document) when one is retrieved asychronously. Search mask should be filled with proper parameters matching the need in hand. If no parameters are given, all headers of Application Themes available in Definition Repository will be delivered, otherwise, only sub-set of theme-headers will be delivered. After the query-call hspsGetListHeaders(), the delivering of the theme-headers is asynchronous. Asynchronous service must be initiated by calling hspsGetNextHeader() after checking that any theme matching on current query is found. This action is called a subscription. To receive theme listing, the client application must implement MhspsThemeManagementServiceObserver-interface and start to listen call-back messages. The headers matching on query will be delivered immediately. Query remains until hspsCancelGetListHeaders() is called by client. If a new Application Theme exist in repository, it will be delivered. As mentioned, when hspsGetListHeaders() returns, the return value must be checked. Return value could be one of the following:

EhspsGetListHeadersSuccess - there is at least one Application Theme available matching on query. Call first hspsGetNextHeader() to get the headers. Same call will set the subscribtion of new ones possible coming available later on.

EhspsGetListHeadersEmpty - there is no themes matching on the query available at the time, however, some might be exist later in due to installations. Client application should retain the subcription.

EhspsGetListHeadersFailed - service request failed in some reason. Possible reasons are for e.g. the missing rights to list headers queried.

EhspsGetListHeadersUpdate - header list on the client side has a new object appended at the end of the list,

EhspsGetListHeadersRestart - header list on server side has changed so much that the client must empty the list printed on screen. New list will be delivered immediately. The subscription stands.

EhspsGetListHeadersEmpty - header list on server side is now empty. The client must empty the list on screen if printed. The subscription stands.

EhspsGetListHeadersFailed - operation has failed. Client should cancel request and restart, perhaps.

EhspsServiceRequestSheduled, or

EhspsServiceRequestError.