Wow! Thank you very much for answering my question so quickly! Ok I will try to ask AS agents to block a whole three seats but the problem is that my plane ticket belongs to Qantas and Qantas agents will give me my seat number! Is it possible for me to ask Qantas agents about it so that they can change it for me?

well..I'm going to fly in July, i believed that there arent may pax to Canada!