You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I would like to change my flight reservation as I am unwell, can you please help me?

ASSISTANT: Sure, I can help you with that. May I know your good name please?

USER: My name is Jack Smith.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Jack Smith, there is no active reservation found under your name to do changes in that.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for choosing us.