You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Patrick Williams here.

ASSISTANT: How can I help you?

USER: I would like to change my recent reservation because of some personal health issue. Can you help me to change this reservation?

ASSISTANT: Sure, I'll help you in that. Please be on hold.

USER: Sure.

ASSISTANT: There is no reservation found under your name to do changes in that.

USER: That's fine, thanks for your information.

ASSISTANT: Thank you for choosing us.