You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Jacob Green here.

ASSISTANT: How may I render you today?

USER:  Due to sudden change of my business meeting due to  some technical problem, I need to change my reservation.

ASSISTANT: Ok.

USER: Will you help me in this?

ASSISTANT: Sure.

USER: Thank you.

ASSISTANT: Please wait a minute.

USER: Ok, I will wait.

ASSISTANT: There is no reservation found on your name to proceed further.

USER: Ok, thank you for your information.

ASSISTANT: Thank you.