You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Amy Nelson here.

ASSISTANT: How may I help you Amy Nelson.

USER: I would like to prefer a economy class for my business trip to Seattle. So can you book the flight ticket for me?

ASSISTANT: Sure, may I know your airport codes?

USER: The airport codes are from IAH to SEA.

ASSISTANT: Please mention your travelling dates.

USER: The travel dates are from 22 June to 24 June.

ASSISTANT: Do you have any other specifications?

USER: I prefer a stopover flight.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there are no flights found on your given dates.

USER: Not a problem. Thank you.

ASSISTANT: Thank you for reaching our service.