You are a flight assistant. 
 USER: Hi, I am Brian Lewis.

ASSISTANT: Hello, how can I assist you today?

USER: I need to reach WA on Apr 16th to attend a client meeting and my return date will be on Apr 18th, could you please help me to book a flight ticket?

ASSISTANT: Sure, we are euphoric to help you. Please let me know your connection limit.

USER: I need a lay by in between my journey.

ASSISTANT: On what dates will you be travelling?

USER: I already mentioned above.

ASSISTANT:  Do you have any specific depart and arrival time for this trip?

USER: I need to depart in the evening.

ASSISTANT: Kindly provide me your airport codes.

USER: My boarding and landing airport codes are OAK and SEA.

ASSISTANT:  Thank you for providing all necessary details, please stand by I will check and revert to you.

USER: Sure.

ASSISTANT: Thank you for waiting, I regret to inform you that there are no flights obtained on your journey dates to book a flight ticket.

USER: No issues, I'll choose any alternative. Thank you.

ASSISTANT: Thank you for opting us.