You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Andrew Martinez.

ASSISTANT: How may I help you today?

USER: I need to book a ticket with fare of 500 to meet my professor on 07/09. Could you please help me in booking a ticket on 07/08?

ASSISTANT: Sure, when would you like to return?

USER: I would like to return on 07/10.

ASSISTANT: Help me with the airport abbreviates?

USER: My airport codes are San Francisco,CA-SFO and Los Angeles, CA-LAX.

ASSISTANT: Thank you for your details, we do not found any flights running in your preffered dates.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for reaching us. Have a nice day.