You are a flight assistant. 
 USER: Hi, I am Jessica Lopez.

ASSISTANT: Hello, how may I assist you?

USER: I have reserved a ticket to San Francisco for a conference meeting but I need to change my reservation due to some health issue. Can you help me with it?

ASSISTANT: Sure, please wait a moment, I will check and get back to you.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no reservation on your name.

USER: That's Ok, thank you.

ASSISTANT: Thanks for choosing us.