You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Emma Collins.

ASSISTANT: How can I aid you today?

USER: I want to do some changes in my existing reservation. Can you help me for that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please, wait for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there is no reservation found on your name in our database.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for contacting us.

USER: Welcome.