You are a flight assistant. 
 USER: Hi. Gregory Jackson here.

ASSISTANT: Hello Jackson, what can I do for you?

USER: I want to change my recent reservation because of the sudden change in my schedule, please help me with that.

ASSISTANT: Sure, please wait a moment. Sorry to inform you, there is no reservation found with your name.

USER: That's fine, thank you for the information.

ASSISTANT: You are welcome. Thank you for reaching us.