You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: Could you please help me in changing my existing reservation under the name of Barbara Hernandez?

ASSISTANT: Sure, I am euphoric to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: I don't see reservation on your name in our database.

USER: Not a problem, thank you.

ASSISTANT: Thank you.