You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: My name is John Anderson. Owing to emergency, I need to change my recent reservation. Please help me with that.

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please give me a moment to check you reservation status.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name in our records.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for choosing us.