You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Elizabeth Lopez here.

ASSISTANT: How may I assist you today?

USER: Can you please reserve me a flight ticket from SEA to IAH?

ASSISTANT: Sure, I will help you. Please help me with your planned travelling dates.

USER: My trip dates are 03/21 - 03/23.

ASSISTANT: Do you need a break in your journey?

USER: I need a direct flight.

ASSISTANT: Do you have any other preferences in your journey?

USER: No.

ASSISTANT: Please allow me a minute.

USER: Ok.

ASSISTANT: Elizabeth Lopez, I am really sorry to inform you that there are no flights available for your journey.

USER: Not an issue, thank you.

ASSISTANT: Thank you for reaching us. Have a great time.