You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I just want to change an existing reservation due to my exam got post pone, can you help me?

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

USER: I am Sharon Brown.

ASSISTANT: Ok, give me a minute.

USER: Sure.

ASSISTANT: Thank you for being patient. We found no reservation by your name.

USER: Ok, no issue.

ASSISTANT: Thank you for approaching us.

USER: Thank you.