Description
resource 
ibase_set_event_handler ( callback event_handler, string event_name1 [, string event_name2 [, string ...]] )
resource 
ibase_set_event_handler ( resource connection, callback event_handler, string event_name1 [, string event_name2 [, string ...]] )
     This function registers a PHP user function as event handler for the specified
     events. The callback is called with the event name and the link resource as arguments
     whenever one of the specified events is posted by the database. The callback must
     return FALSE if the event handler should be canceled. Any other return value is ignored.
     This function accepts up to 15 event arguments.
    
     
    
     The return value is an event resource. This resource can be used to free the event handler
     using ibase_free_event_handler().
    
     See also
     ibase_free_event_handler() and
     ibase_wait_event().