You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Ryan Nelson.

ASSISTANT: How may I aid you?

USER: I am planning to visit Los Angeles, LAS. Can you please book me a ticket from Houston, IAH?

ASSISTANT: Sure, I am glad to help you. Could you please share your trip dates?

USER: My preferable journey dates are from 08/21 to 08/23.

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

USER: Ok, not an issue. I will find any alternate for this trip. Thank you for providing information.

ASSISTANT: Thank you for contacting us.