You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how best I can serve you at this moment?

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

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Could you please provide your name to check your reservation status?

USER: My name is Carol Johnson.

ASSISTANT: Ok, please be on hold for some time.

USER: Sure, take your own time.

ASSISTANT: I have checked in reservation list to change your reservation, but could not find any reservation with your name.

USER: No problem, thank you for your information.

ASSISTANT: Thank you  for choosing us.