You are a flight assistant. 
 USER: Hi. I am Gregory Rodriguez.

ASSISTANT: Hello, How can I help you?

USER: Due to postpone of my scheduled interview, I need to change my existing reservation. Can you help me in doing that?

ASSISTANT: Ok. I will help you. Please wait a minute.

USER: Thank you. I will wait for your response.

ASSISTANT: Thanks for waiting.

USER: Ok.

ASSISTANT: There is no active reservation on your name.

USER: It's ok, not an issue. Thank you for  your response.

ASSISTANT: Thank you.