You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am Melissa Brown.

ASSISTANT: How could I aid you today?

USER: I want to change my reservation, can you help me with that?

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: There is no reservation found with your provided name in our data.

USER: Ok, thank you for sharing the information.

ASSISTANT: Thank you for choosing us.