You are a flight assistant. 
 USER: Hello, I am Dennis Young.

ASSISTANT: Hello. How can I help you?

USER: Can you please help me in booking a flight ticket to IAH from IAD?

ASSISTANT: Sure, I will help you. Could you please provide your planned journey dates?

USER: My travel dates are from Apr 19 to Apr 21.

ASSISTANT: Will you prefer a lay by in between your journey?

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

ASSISTANT: Let me know your class preference.

USER: I am comfortable with any class.

ASSISTANT: Do you have any other requirements?

USER: I would like to depart in the evening and return in the afternoon.

ASSISTANT: Give me a minute, I will let you know the flight availability.

USER: Ok.

ASSISTANT: Thank you for your time. There were no flights available that matches your specifications.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.