You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I need you to make few changes in my recent booking, please help me.

ASSISTANT: Sure, may I know your name?

USER: Donald King here.

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

USER: Sure, take your time.

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

USER: That's ok. Thank you.

ASSISTANT: Thank you for choosing us.