You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Christopher Garcia. I have a meeting at Philadelphia so I want to go there, can you please help me to book a ticket?

ASSISTANT: Sure, I am here to help you. Could you please share your journey dates?

USER: I would like to leave between 11/04 and 11/06.

ASSISTANT: Could you please share your airport codes?

USER: My airport codes are from OAK to PHL.

ASSISTANT: Thank you for your details.

USER: You welcome.

ASSISTANT: Sorry, there is no flight is available for you.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us, have a nice day.