You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. Can you please tell me how can I assist you?

USER: Daniel Green here. Can you please help me out in booking a ticket from IAH to JFK?

ASSISTANT: Ok, may i know your travel dates?

USER: Sure, my journey dates are 05/26 and 05/28.

ASSISTANT: Sorry, no flights.

USER: That's ok, thank you for your service.

ASSISTANT: Thank you for reaching us.