You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Sandra Garcia.

ASSISTANT: How can I assist you today?

USER: Due to some entrepreneurship meeting, I am going to change my existing reservation. Can you please help me in changing the reservation?

ASSISTANT: Please give me a moment, I will check and get back to you.

USER: Sure.

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

USER: No problem, thanks for your information.

ASSISTANT: Thank you for choosing us.