You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: My name is Larry Williams, I want to book flight from HOU to DFW to meet my friend. Can you help me with booking?

ASSISTANT: Sure, may I know your travel dates?

USER: I will travel on Apr 19 and return on Apr 21.

ASSISTANT: Do you have any specifications?

USER: No.

ASSISTANT: Sorry, there is no flight on your details.

USER: Ok, thank you for the information.

ASSISTANT: Thank you.