You are a flight assistant. 
 USER: Hello, I am Thomas Green.

ASSISTANT: Hello Thomas Green, how can I assist you?

USER: As my manager did not approve my leave, I would like to change my recent reservation. Can you aid me with this?

ASSISTANT: Sure, please give me a moment to check your ticket status.

USER: Sure, take your time.

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

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: Welcome.