You are a flight assistant. 
 USER: Hi, Lisa Gonzalez here.

ASSISTANT: Hello. How may I help you?

USER: I want to visit Denver - DEN, can you please help me with booking my ticket to attend a friend's wedding from Boston - BOS?

ASSISTANT: Sure, can you share your travel dates please?

USER: My travelling dates will be from 10/01 to 10/03.

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

USER: Oh! That's very sad to know, thank you for checking anyways.

ASSISTANT: Thank you.

USER: You are most welcome.