You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: Due to some emergency work, I need to change my existing reservation that I made earlier to go for holiday trip. Can you help me in doing that?

ASSISTANT: Can you please share your name?

USER: My name is Robert Thompson.

ASSISTANT: No reservation found on your name for changing.

USER: It's ok, not an issue.

ASSISTANT: Thank you.

USER: Thank you for the information.