You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Lisa Adams.

ASSISTANT: How can I aid you?

USER: I had planned to go on a trip with my friends, but it was postponed due to health problem of my friend. Can you help me in changing my recent reservation?

ASSISTANT: Sure, just a second please.

USER: Ok.

ASSISTANT: Sorry to say no reservation found on your name.

USER: That's Ok.

ASSISTANT: Thank you for choosing us.

USER: Anyways, thank you for your help.

ASSISTANT: Your welcome.