I suggest never get currency from the departing or arriving airport currency exchange counters. Their conversion rate is with a high margin and also commission and charges. Local banks and licensed foreign exchange dealers ( not every one ) who deal with foreign exchange will be better than airports. Still need to make a comparison among them. Those who are in the Middle East can buy CAD currency from the Money exchange kiosks, who don't take commission. Dealers are not maintaining the same rate of exchange. Better to monitor the exchange rates every day over phone or in the media and purchase when you find a better rate.
Thanks senior for the advise...Will keep that in mind