You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you today?

USER: Can you help me change my existing reservation which was made on the name of Paul Gonzalez?

ASSISTANT: Sure, give me some time I will check is there any reservation with this name.

USER: Sure.

ASSISTANT: Thank for waiting, unfortunately we did not found any reservation on this name.

USER: It's ok, thank you for the response.

ASSISTANT: Thanks for opting us.