You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hi.

USER: I'm Richard Evans.

ASSISTANT: How can I help you?

USER: I want to visit a historical place in Minneapolis.Can you book a ticket from IAH to MSP?

ASSISTANT: Sure, your date of travelling?

USER: I want to depart on 08/19 and return is on 08/21. The connection limit is 1.

ASSISTANT: I am sorry no flights available on your details. Thank you.

USER: That's Ok. Thank you for your help.