You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I render you?

USER: Could you please change my existing reservation due to postpone of my trip?

ASSISTANT: Sure, may I know your name?

USER: My name is Charles Gonzalez.

ASSISTANT: Please give me a moment to check your ticket status.

USER: Sure, take your time.

ASSISTANT: Sorry Charles Gonzalez, no reservation is available by your name.

USER: Not a problem, thank you for checking.

ASSISTANT: Thank you for reaching us.