CURSOR HELP

HELP. I apologize if this is too basic, but since I have next to zero
documentation on it I must ask... Can you declare and use CURSORs using
plpgsql? The documentation I have read seems to indicate that you can,
but I have not been able to get it to work. I can get a similar function
to work in SQL from the command prompt, but not when using a plpgsql
function. Here is a snippet of code:

   DECLARE recur_events_curs CURSOR FOR
      SELECT time_start,
             time_end
        FROM CHAT_EVENT
       WHERE day_of_week = v_day_of_week
         AND id_resource = v_id_resource;

   v_this_start_time CHAT_EVENT.time_start%TYPE;
   v_this_end_time CHAT_EVENT.time_end%TYPE;

   IF v_end_time <= v_start_time THEN
      /* Recurring event spans two days of the week */
      v_use_end_time := v_end_time + 2400;
   ELSE
      v_use_end_time := v_end_time;
   END IF;

   /* First, determine if this event overlaps any recurring events */
   OPEN recur_events_curs;
   LOOP
      FETCH recur_events_curs INTO v_this_start_time, v_this_end_time;
      EXIT WHEN recur_events_curs ISNULL;

I always get an error on the "CURSOR" during compile of function.

Thanks,

Rudy