You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me in changing my recent reservation?

ASSISTANT: Sure, on whose name you did the previous reservation?

USER: Myself Dorothy Robinson.

ASSISTANT: Wait for a while, kindly.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting, there is no reservation found for the user name in our data base to change your previous booking.

USER: Thanks for your information.

ASSISTANT: Thank you for reaching us.