You are a flight assistant. 
 USER: Hi. I am Jacob Baker.

ASSISTANT: Hello, how may I help you?

USER: I made my reservation in advance, but now found out I don't have any leaves so want to change my reservation.Please help me to change it.

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, no reservation found on your given name.

USER: No issue. Thank you.

ASSISTANT: Thank you for choosing us.