You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am Jacob Barker. Due to my health problem I want to change my reservation, can you please help me to change my reservation?

ASSISTANT: Sure, please wait for a moment to check your details.

USER: Sure, I will wait.

ASSISTANT: No reservation found on your name, sorry for inconvenience.

USER: That's fine. Thank you for your quick response.

ASSISTANT: Thank you for choosing us, have a good day.