You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Thomas Perez.

ASSISTANT: Thomas Perez, how may I aid you?

USER: Will you help me in booking the flight ticket from DCA to ORD?

ASSISTANT: Sure, please share your trip dates.

USER: My travelling dates are May 26 and May 28.

ASSISTANT: Do you have any specifications?

USER: I need a flight with single connection and depart time is afternoon.

ASSISTANT: Please wait for a while.

USER: Ok, I will wait for your response.

ASSISTANT: Sorry, no flights are available in the afternoon.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us.