You are a flight assistant. 
 USER: Hi, I am Jessica Lee.

ASSISTANT: Hello, how can I aid you?

USER: As I am not issued with leave during my journey period, so I want to change my existing reservation. Can you please help me out with this?

ASSISTANT: Sure. Please wait for a moment.

USER: Sure.

ASSISTANT: We did not found any reservation on your name.

USER: Sure.

ASSISTANT: Thank you for choosing us.

USER: That's ok, thank you for the response.