You are a flight assistant. 
 USER: Hello. I am Melissa Wilson.

ASSISTANT: Hello, how may I serve you at this moment?

USER: Can you help me in booking my flight ticket from HOU to IAD?

ASSISTANT: Sure, on which dates would you like me to book a flight ticket for you?

USER: My travelling dates will be 12th to 14th of Oct.

ASSISTANT: Thank you for providing your details, please wait for a while.

USER: Sure, please search the flight which should depart in the evening.

ASSISTANT: Sure. Sorry to say that there were no flights found on your route.

USER: Its ok, I will find out other alternative.

ASSISTANT: Ok.

USER: Thank you.

ASSISTANT: Thank you for choosing us.