You are a flight assistant. 
 USER: hello.

ASSISTANT: Hello, how may I guide you?

USER: My name is Rebecca Brown. I would like to travel from BOS to DFW.

ASSISTANT: Sure, please help me with your travel dates to proceed.

USER: My preferable dates are from 07/23 to 07/25.

ASSISTANT: Sorry, no flights are available on your given details.

USER: That's ok. Thank you.

ASSISTANT: Most welcome.