You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you?

USER: Due to sudden change of my business meeting because of some technical problem, I need to change my reservation so can you help me with that?

ASSISTANT: Sure, I am ready to help you with that. On which name  you have  booked your previous reservation?

USER: I am Emma Miller.

ASSISTANT: Ok, please allow me a couple of seconds to check your ticket status.

USER: Sure.

ASSISTANT: I regret to tell you that, I haven't found your previous reservation in our database to change the details.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: You are welcome. Thank you for choosing us.