You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be at your service today?

USER: I am Joshua Allen. Can you please help me to book a flight ticket from Houston to Chicago?

ASSISTANT: Sure, may  I know on which dates would you like to book your flight ticket?

USER: Thank you. I have planned to travel on the dates of April 7th and April 9th.

ASSISTANT: Do you prefer any class in your journey?

USER: I didn't have any class preference but I need a flight which is departing in the  morning.

ASSISTANT: Ok, please wait for a while. May I know the airport code of Houston?

USER: The source and destination airport codes are IAH and ORD.

ASSISTANT: Sorry, there are no flights found matching your details.

USER: It's ok, not a problem with that. Anyways thank you for your time.

ASSISTANT: Thank you for choosing us.