You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you at this minute?

USER: Could you help me to book a economy class flight ticket from MSP to BOS?

ASSISTANT: Ok, I will help you with that. Can I know your travelling dates?

USER: I will travel on June 12th and 14th.

ASSISTANT: Do you have any other specifications?

USER: I would like to depart in the evening time and please look for an normal-cost airline's flight.

ASSISTANT: Do you have any other requirements?

USER: I am fine with a connecting flight.

ASSISTANT: Sorry to say that, there are no flight's available based on your travelling dates.

USER: Not an issue, will find an alternative. Thank you.

ASSISTANT: Thank you for reaching us. May I know your name?

USER: My name is Ryan Lopez.

ASSISTANT: Thank you.