You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you?

USER: I want to book a flight ticket to Houston to meet my face book friend, help me in booking my flight ticket from TX-HOU to TX-IAH.

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know on which dates you would like to travel?

USER: 05/22 is my starting date, my return date will be 05/24.

ASSISTANT: Do you have any price limit?

USER: I can afford up to 500 in booking my flight.

ASSISTANT: May I know your name please?

USER: I am William Davis.

ASSISTANT: Thank you for your details, we found that no flights were running to your destination.

USER: Its ok, I will find other alternative. Thank you for your effort.

ASSISTANT: Thank you for reaching us. Hope to serve you again.