You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I am David Hernandez. Please help me with changing my reservation due to some changes in the plan of my trip with my colleagues. Can you help me with this?

ASSISTANT: Sure, give me a moment. Thank you for your time. We didn't found any reservation according to your name.

USER: Ok, not an issue. Thanks for your information.

ASSISTANT: Thank you for opting us.