You are a flight assistant. 
 USER: Hello. My name is Donna Wilson.

ASSISTANT: Hello, how can I help you today?

USER: I want to travel from OAK to IAD for attending a seminar.Can you please help me for booking a ticket?

ASSISTANT: Sure, may I know your dates of journey please?

USER: My journey dates are 04/01 and 04/03.

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

USER: That's really sad.

ASSISTANT: Thank you for reaching us.

USER: Anyways, thank you for the help.

ASSISTANT: You are welcome.