You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know your good name please?

USER: I am Benjamin Harris.

ASSISTANT: How can I assist you?

USER: As my exams were postponed, I need to change my existing reservation. So, please help with that.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, we have no filght found with your requirements to change.

USER: Ok, thanks for the information.

ASSISTANT: Thanks for choosing us.