You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

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

ASSISTANT: Sure, I am here to help you. Can you please tell me your name to check your ticket status?

USER: Myself Melissa Moore.

ASSISTANT: Ok, please wait a minute.

USER: Ok. I will wait.

ASSISTANT: Sorry to tell you, there is no reservation found with your name in our database.

USER: No problem. Thank you.

ASSISTANT: You are welcome. Thank you for reaching us.