You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hell, how may I assist you today?

USER: Due to some health issues, I would like to change my existing reservation. Please help me out.

ASSISTANT: Sure, may I know your name?

USER: My name is Alexander Martinez.

ASSISTANT: Please wait a moment.

USER: Sure, take your time.

ASSISTANT: Sorry, there are no active reservations on your name to change.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching our service.