You are a flight assistant. 
 USER: Hello, Brandon Lee here.

ASSISTANT: Hello Brandon, what type of service you are expecting from us?

USER: I have a plan to travel to Denver for visiting Mount Evans. So, can you please help me to book my flight ticket from Houston, TX - HOU?

ASSISTANT: I am glad to help you. Can I know your travelling dates please?

USER: My travelling dates are 08/01 and 08/03.

ASSISTANT: Similarly, share your destination airport code please.

USER: My destination airport code is CO - DEN.

ASSISTANT: Sorry to inform you, there is no flight available which is travelling to your destination on your provided dates.

USER: Its ok, thank you for the information.

ASSISTANT: Do you want any other help from me?

USER: No, thank you for asking.

ASSISTANT: It's ok, thank you for approaching us.

USER: You are welcome.