You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Margaret Lopez here.

ASSISTANT: How can I assist you today?

USER: I want to travel from ATL to LAS for a business conference, can you please help me out with booking of a flight ticket?

ASSISTANT: Sure, will you mention your travelling dates please?

USER: Sure, I am planning to move on 09/19 and please book my return ticket on 09/21.

ASSISTANT: Please give me a moment.

USER: Ok, take your time.

ASSISTANT: There is no flights found under your preferable details.

USER: Oh! So sad to hear. Anyway, thank you for the information.

ASSISTANT: Thank you for reaching us. Have a great day.