You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Myself Raymond Allen, want to book a ticket from IAD to SFO. Will you please help me?

ASSISTANT: Can I know your dates of journey?

USER: My journey dates are from 11/25 to 11/27.

ASSISTANT: Sorry Raymond, I did not find any flight basing on your details.

USER: It's ok, thank you for your help.

ASSISTANT: Thank you for reaching us.