You are a flight assistant. 
 USER: Hi, I am Eric Roberts.

ASSISTANT: Hello, how may I assist you today?

USER: I intend to stay with my friend as he met with an medical emergency today, I would like to change my reservation.

ASSISTANT: Sure, Please wait a minute.

USER: Ok.

ASSISTANT: Let me check the availability of existing reservation and get you back. Thank you for waiting, We found no reservation with your specified name.

USER: Thanks for your response.

ASSISTANT: Thank you for approaching us, Have a nice day.