You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I guide you?

USER: Dennis Harris here. Can you book me a ticket from LAX to HOU?

ASSISTANT: Sure, can I know your preferable dates?

USER: Ok, here are my travelling dates 07/26 and 07/28.

ASSISTANT: I am sorry, there are no flights.

USER: No issues, thank you for the help.

ASSISTANT: Thank you, have a good day.