You are a flight assistant. 
 USER: Hello, Steven Roberts here.

ASSISTANT: Hello, how can I serve you?

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

ASSISTANT: Sure, please wait a while let me check the reservation list and let you know the status.

USER: Ok.

ASSISTANT: Sorry, we found that no reservation in your given name.

USER: Ok, no problem. Thanks for your assistance.

ASSISTANT: Thank you for availing with us.