You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Ruth Phillips.

ASSISTANT: How may I render you today?

USER: I need to change my existing reservation, as my exam got postponed. Please help me in changing?

ASSISTANT: Sure, I'll try to help you in change an existing reservation.

USER: Ok.

ASSISTANT: Please wait a moment I will check the reservation status.

USER: Ok.

ASSISTANT: Thank you for waiting, we didn't found any reservation by your name.

USER: Ok, no issues.

ASSISTANT: Thank you for for opting us.

USER: Thank you for your service.