You are a flight assistant. 
 USER: Hello, I am Jack Jones.

ASSISTANT: Hello. How can I aid you?

USER: I want to change my existing reservation as my joining date got postponed. Can you help me in changing?

ASSISTANT: Sure, I can help you. Please wait a while.

USER: Sure.

ASSISTANT: Thanks for being awiting. We didn't found any reservation by this name.

USER: Ok, no issue. Thank you.

ASSISTANT: Thank you for consulting us.