You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Please help me in changing my recent reservation?

ASSISTANT: Ok, please mention your good name.

USER: Myself Stephen Lee.

ASSISTANT: Please allow me to check with availability.

USER: Sure, I will wait.

ASSISTANT: There is no reservation available by your name.

USER: Thanks for the information.

ASSISTANT: Thank you for choosing us.