You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Dennis Anderson.

ASSISTANT: How can I help you?

USER: I need to go Washington to meet my friend so please help me with flight ticket booking from Las Vegas.

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Could you please share your planned journey dates?

USER: Sure, I have planned to travel on dates of Aug 14 and Aug 16.

ASSISTANT: May I know, from which airport you are planning to take off?

USER: Sure, I would like to travel from LAS to IAD.

ASSISTANT: Let me know your connection limit.

USER: I am looking for single connecting flight but even direct flight is also fine with me.

ASSISTANT: Which class would you prefer for your journey?

USER: I am ok with any class actually.

ASSISTANT: Do you have any other preferences?

USER: Yes, I would like to depart in the afternoon time.

ASSISTANT: Give me a minute, I will let you know the flight availability.

USER: Sure, I will wait for your response.

ASSISTANT: Thank you for your time.

USER: It's ok.

ASSISTANT: I am sorry to inform you that, there were no flights available that matches your requirements.

USER: It is very sad to hear. I have to visit another agency this time. Anyway, thank you for your time.

ASSISTANT: Thank you for approaching us.