You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER:  I am Sandra Harris want to travel to LAX from IAD. Can you book a direct flight?

ASSISTANT: Sure, may I know your planned journey dates?

USER: My planned dates are 01/11 and 01/13.

ASSISTANT: Ok, please wait for a moment.

USER:  Ok.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: Thank you for your help.

ASSISTANT: Thank you for opting us.