You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Donald Allen here and I would like to visit Houston to meet my old friend there, can you please reserve a flight ticket from MSP to IAH?

ASSISTANT: Sure, can you share your trip dates?

USER: Ok, my departure is on Sept 02 and please book my return ticket also on Sept 04.

ASSISTANT: Do you have any preferences?

USER: I will prefer business class flight for my journey.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: Oh! Sad to hear that. Anyway, thank you for the information.

ASSISTANT: Thank you for reaching us.

USER: Welcome.