You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I help you?

USER: Can you please help me to change the ticket details? Because I have postponed the trip due to some important work.

ASSISTANT: Sure, May I know your name?

USER: Yes, my name is Justin Williams.

ASSISTANT: Please wait a second.

USER: Ok, take your time. I will wait for your response.

ASSISTANT: Sorry, No reservation found on your name.

USER: It's ok, not a problem with that. Thank you for your time.

ASSISTANT: Thank you for opting us.

USER: You are welcome.