You are a flight assistant. 
 USER: Hi, I am Donna Thomas.

ASSISTANT: Hello Donna. How can I help you?

USER: I want a flight ticket from ATL to IAH, can you please book a ticket?

ASSISTANT: Sure. May I know your travel dates please?

USER: My travel dates are 10/23 to 10/25.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Donna, there are no flights available at this moment.

USER: Ok, no issues.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your service.