Ada Queue

["Joseph T." <thisthat7@hotmail.com>]

Can anyone corroborate why I chose to make this enqueue function using the
passed pointer to Q instead of the temp pointer to loop through the queue?
 Any suggestions, ideas, compliments, critiques are greatly appreciated.
 Please help.

procedure Enqueue(Q: in out Queue; E : Element_type) is
   New_Queue : Queue;

begin
   if Q /= null then
       New_Queue := Q;
       while Q.Rest /= null loop
          Q := Q.Rest;
       end loop;
       Q.Rest := new QueueNode;
       Q := Q.Rest;
       Q.Data := E;
       Q.Rest := null;
       Q := New_Queue;
   else
       Q := new QueueNode;
       Q.Data := E;
       Q.Rest := null;
   end if;
end Enqueue;