You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you at this moment?

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, may I know your name for further process?

USER: Ok, my name is Raymond Clark.

ASSISTANT: Ok, please hold on a moment.

USER: Sure, I will wait.

ASSISTANT: There is no previous reservation available under your name.

USER: Ok, not an issue. Anyways, thank you for your service.

ASSISTANT: Thank you for reaching us.