You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Stephanie Martinez. I just want to change my existing reservation, due to sudden demise of my grand mother.

ASSISTANT: Sure Stephanie Martinez, let me check the present status.

USER: Ok.

ASSISTANT: Thank you for waiting, sorry to inform you that unfortunately there is no flights available by the given details.

USER: It's Ok, thanks for your response.

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