You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: Joseph Garcia here. I need to change my existing reservation as my sister blessed with a baby before the expected delivery date.

ASSISTANT: Sure, please allow me a moment to check for the availability of flight.

USER: Ok.

ASSISTANT: Joseph, there is no reservation found under your name.

USER: That's ok, thank you for your help.

ASSISTANT: Thank you for contacting us.