You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Due to sudden change in my trip to another location, I would like to do some changes in existing my reservation. Can you please help me out?

ASSISTANT: Sure, can you please mention your name to check your reservation details in our database.

USER: Myself Melissa Hall.

ASSISTANT: Thank you. Please wait for a while, let me check your reservation status.

USER: Ok.

ASSISTANT:  I am very sorry to inform you that there is no reservation found under your name in our database.

USER: Thank you so much.

ASSISTANT: Thank you for reaching us.