Sir, - Has the Aer Lingus marketing department lost the run of itself entirely? Why do you suppose it chooses to advertise its economical flights to Zurich (The Irish Times, April 17th) with a photograph of Bruges, brooding medieval city? Would it be prepared to reimburse disgruntled weekenders who found themselves in the sleek Swiss city rather than this astonishing corner of Belgium? - Yours, etc.,Joe Vanek,Arnott Street,Dublin 8.