You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: I need to change my reservation due to urgent meeting, can you help me?

ASSISTANT: Yes, can you tell me your name?

USER: I am George Thompson.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: That's ok. Thank you.

ASSISTANT: Thank you for contacting us.