You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you today?

USER: I want to change my existing reservation which is done recently due to some problems, can you please help me in this?

ASSISTANT: Sure, I am glad to help you with that. Can you please share your name?

USER: Sure, my name is Amanda Thomas.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there is no active reservation found on your name in our database.

USER: Ok, no problem.

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

USER: Anyways, thank you for your service.