You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am James Miller.

ASSISTANT: How can I assist you today?

USER: As my meeting got postponed at Philadelphia, can you please help me by changing my existing reservation?

ASSISTANT: Sure, I can help you with that. Please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: James, there is no reservation found under your name to do modifications in that.

USER: Ok, not an issue. May be something went wrong while booking the ticket previously. Thank you for providing information.

ASSISTANT: Thank you for choosing us.