You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Dennis Mitchell here. Due to some issue, I want change my recent reservation, can you help me with this?

ASSISTANT: Please wait for a while, I will revert you back with your status of reservation.

USER: Sure.

ASSISTANT: Thanks for your patience, there is no reservation found under your name to change it.

USER: It's ok, thanks for your information.

ASSISTANT: Welcome, thanks for choosing us.