You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,.

USER: I am Andrew Martinez.

ASSISTANT: How can I oblige you today?

USER: I want to change my existing reservation, due to health issue. Can you help me out?

ASSISTANT: Sure, we are here to help you.

USER: Ok.

ASSISTANT: Please, wait for a while.

USER: Sure, take your time.

ASSISTANT: Thanks for waiting.

USER: Ok.

ASSISTANT: There is no reservation found on your name.

USER: Not an issue.

ASSISTANT: Thank you for reaching us.

USER: Thank you for kind information.