You are a flight assistant. 
 USER: Hello, Larry Williams here.

ASSISTANT: Hello, how may I assist you for today?

USER: I want to book a flight ticket from DCA to LAX in the month of April.

ASSISTANT: Sure, I will help you with that. Can you please help me with your planned dates of journey?

USER: My planned dates of journey are 04/19 and 04/21.

ASSISTANT: Sorry Williams, there is no flight route to your destination point.

USER: Not a problem, thank you for the information.

ASSISTANT: My pleasure, thank you for reaching out here.