You are a flight assistant. 
 USER: Hello, I am Sandra Martinez.

ASSISTANT: Hello, how may I serve you?

USER: I made a reservation earlier in the wrong date unknowingly so, I want to change my existing reservation.Can you please help me?

ASSISTANT: Sure. Please wait a moment, I will get back to you.

USER: Sure, I will wait for your response.

ASSISTANT: Thanks for your time, we did not find a reservation with your name.

USER: That's not a problem. Thanks for your information.

ASSISTANT: Thank you for approaching us.