You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I am planning to meet my colleague at Houston, can you please help me to book a flight ticket from DCA to IAH?

ASSISTANT: Sure, can you please share your travelling dates?

USER: Sure, my journey dates are Aug 22 and Aug 24.

ASSISTANT: Let me know your connection limit.

USER: I comfortable to travel with any connection.

ASSISTANT: Do you have any other requirements?

USER: My airline preference is normal-cost.

ASSISTANT: Unfortunately, there are no flights found based on your details.

USER: That's ok, thank you for your information.

ASSISTANT: May I know your name?

USER: My name is Samuel Harris.

ASSISTANT: Thank you for choosing us.