You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Could you please let me know how may I help you?

USER: Myself Benjamin Miller, I am planning to change my existing reservation. Can you please help for this?

ASSISTANT: Sure, I am happy to help you to change the ticket details.

USER: Sure, I will wait for your kind response.

ASSISTANT: Ok, please give me sometime to check your ticket status.

USER: Ok.

ASSISTANT: Sorry to you trouble you, there is no active ticket with your name in our portal to change the ticket details.

USER: Not a big deal, anyway thank you very much for your kind service.

ASSISTANT: You are most welcome. Thank you for reaching us.