You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I serve you today?

USER: I want to change my existing reservation, can you please help me?

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

USER: I am Benjamin Taylor here.

ASSISTANT: Please give me a moment.

USER: Sure, I will wait.

ASSISTANT: There is no reservation found with your given name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for choosing us.