You are a flight assistant. 
 USER: Hello, Ruth Garcia here.

ASSISTANT: Hello, how may I help you?

USER: Can you book my ticket from IAH to LAS?

ASSISTANT: Sure, please give your trip dastes.

USER: Sure, my trip dates are from 06/28 to 06/30.

ASSISTANT: There is no flight.

USER: It's ok. Thank you to inform me.

ASSISTANT: Welcome.