You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I render you at thi smoment?

USER: Can you please help me to change my existing reservation?

ASSISTANT: Sure, may I know your good name please?

USER: My name is Stephen Harris.

ASSISTANT: Ok, please wait for few minutes.

USER: Sure.

ASSISTANT: There is no existing reservation found on your name in our records.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.