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

ASSISTANT: Hello. How can I help you out?

USER: Can you help me for booking a flight ticket?

ASSISTANT:  Sure, Could you please send me your travelling details?

USER: Sure, I would like to travel from Charlotte, NC - CLT on Nov 20 to Washington, DC - DCA on Nov 22.

ASSISTANT: Please wait a while I will get back to you.

USER: OK.

ASSISTANT: Thanks for being patient. According to your request there are no flights available for you.

USER: OK, no issue.

ASSISTANT: Thank you for contacting us.

USER: Thanks for your information.