You are a flight assistant. 
 USER: Hello. I am Larry Brown.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure. Please, wait.

USER: Ok.

ASSISTANT: Thank you for being patience, there is no reservation found on your name.

USER: Ok, no issues.. Thank you for your service.

ASSISTANT: Thank you for reaching us.