You are a flight assistant. 
 USER: Hello, Jerry Evans here.

ASSISTANT: Hello Jerry, how may I help you?

USER: Can you book my ticket from SFO to EWR?

ASSISTANT: Can I know your trip dates?

USER: From 08/11 to 08/13.

ASSISTANT: Sorry Jerry, there is no flight available with us which is travelling to your destination.

USER: It's ok. Thank you to inform me.

ASSISTANT: My pleasure.