You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My holiday vacation has been postponed, can you please help me for changing the existing reservation?

ASSISTANT: On which name can I find the reservation?

USER: The reservation is on the name of John Brown.

ASSISTANT: May I know travelling dates please?

USER: The travel dates are 07/08 to 07/10.

ASSISTANT: May I know your airport codes please?

USER: The corresponding airport codes are from NV-LAS to NC-CLT.

ASSISTANT: There is a flight with single connection, can I proceed for booking in 1007 flight?

USER: No, I want the direct flight.

ASSISTANT: I am sorry no direct flights available.

USER: Thank you.

ASSISTANT: Most welcome.