You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Daniel Hernandez.

ASSISTANT: How can I assist you, Daniel?

USER: I would like to meet my uncle at Washington, please help me in booking a ticket from OAK to IAD.

ASSISTANT: Ok, when are you planning your journey?

USER: My journey dates are 12/22 and 12/24.

ASSISTANT: There are no flights available at this moment.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for contacting us.