You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello,. May I know, For what kind of service you have visited us?

USER:  I have made an reservation earlier, but now I need to made a few changes for that. As your agent misplaced the travel dates. Can you help me with changing my reservation?

ASSISTANT:  Sure, I can help you with our full and best services.

USER: Thanks for considering my request.

ASSISTANT:  To change your ticket, we need your name to check your reservation status. Can you provide it?

USER: Sure, please check it with my name Anthony Roberts.

ASSISTANT: Thanks for the name, please wait.

USER: Sure, take your own time.

ASSISTANT:  You have waited for my response with patience. I will appreciate for that.

USER: My pleasure.

ASSISTANT: Sorry to say that, we did not find any reservation with name Anthony Roberts, to change your reservation.

USER: That's ok, I think I have reserved the ticket, in another airlines agency. Anyway, thanks for your effort in searching my reservation.

ASSISTANT: Thank you for visiting us. We hope you will visit again. Have a great day ahead!.

USER: I hope so.