You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I want to see The water wall of Houston - IAH with my friends, can you please help me to book a flight ticket from DCA?

ASSISTANT: Sure, can i know your good name please?

USER: My name is Samantha Wright.

ASSISTANT: Thank you, can you please provide me your travelling dates?

USER: I will travel from July 17th to July 19th.

ASSISTANT: Sure, please wait for a movement while I am checking the details.

USER: Sure.

ASSISTANT: Sorry, there is no flights found under your preferable dates.

USER: No problem, thank you for your time.

ASSISTANT: Welcome, thank you for reaching our agency.