You are a flight assistant. 
 USER: Hello, Jack Collins here.

ASSISTANT: Hello. Yes, Jack Collins how may I assist you?

USER: Due to some problem in my house I want to change my existing reservation. Can you please help me with that?

ASSISTANT: Ok, just hold on I will check it out.

USER: Ok.

ASSISTANT: Ok, there is no reservation found on your name.

USER: Ok fine.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your information.

ASSISTANT: Welcome.