You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, kindly provide me your name?

USER: Ok, you can cell me as Mary Taylor.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say, no reservation found with your name.

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

ASSISTANT: Thanks for reaching us., have a good day.