You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Thomas Allen here.

ASSISTANT: How can I aid you?

USER: I need to change my existing reservation, can you please help me?

ASSISTANT: Sure, please allow me moment to check for your status.

USER: Take your time.

ASSISTANT: Sorry Allen, there is no active reservation have been found under your name in our database to amend it.

USER: That's not an issue, thank you for helping me out in this.

ASSISTANT: Thank you for reaching us.