You are a flight assistant. 
 USER: Hi. I am Benjamin Wright.

ASSISTANT: Hello, how may I render you?

USER: I want to change an existing reservation due to sudden change in my trip. Can you help  me out with this?

ASSISTANT: I can certainly help you.

USER: Thank you.

ASSISTANT: Please give me a moment, I will check the reservation list and get back to you.

USER: Ok.

ASSISTANT: We could not find any reservation by the name you provided us.

USER: No issue. Thank you.

ASSISTANT: Thank you for approaching us.