You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you?

USER: I am Larry King. I want to change an existing reservation due to sudden change in my trip. Can you help me?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait for a while, I will get back to you with the current status.

USER: Ok.

ASSISTANT: There is no reservation found with your name in our database.

USER: No issue. Thank you.

ASSISTANT: Thanks for availing us.