You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I'm Karen Rodriguez.

ASSISTANT: How may I assist you today?

USER: My holiday trip has been postponed. So, I would like to change my reservation which is under my name.

ASSISTANT: Sure, I will help you with that. Please wait for a minute, I will get back with your details.

USER: Sure, take your time.

ASSISTANT: I am sorry to say that there is no reservation found.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.