You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I'm Joshua Phillips.

ASSISTANT: How may I help you?

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

ASSISTANT: Sure, please wait for a moment to check your details.

USER: Sure, take your time.

ASSISTANT: No reservation found on your name.

USER: Ok, no issues.

ASSISTANT: Sorry for inconvenience.

USER: Thank you for checking and providing the information.

ASSISTANT: Welcome.