You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am Sharon Roberts.

ASSISTANT: Nice to meet you Sharon.

USER: I would like to visit Houston to meet my friend, can you please help me to book a flight ticket from DEN to HOU?

ASSISTANT: Sure, tell me your travel dates please?

USER: Sure, my travelling dates are June 26 and June 28.

ASSISTANT: Please wait.

USER: Sure, I will wait for your response.

ASSISTANT: Thanks for waiting. But I am sorry to say that there are no flights available.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you.