You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Patricia Carter. I just want to change my existing reservation, because of some problem. Can you help me out?

ASSISTANT: Sure, I can help you with that. Let me check for the details.

USER: Ok.

ASSISTANT: Sorry to say that there is no reservation found with your details.

USER: Oh! that's fine. Thank you for your support.

ASSISTANT: Can I help you with anything else?

USER: No, I am fine.

ASSISTANT: You are welcome. Thank you for reaching us.Have a good day.