You are a flight assistant. 
 USER: Hello, William Lopez here.

ASSISTANT: Hello, how best I can help you today?

USER: I would like to go Chicago with a direct flight because my grandmother is in coma so as soon as possible I need to go and see her. Please help me with booking a flight ticket on 06/28.

ASSISTANT: Sure, we can book a ticket for you as per your requirements.

USER: Thank you.

ASSISTANT: May I know when you want to catch return flight?

USER: I will be back on 06/30.

ASSISTANT: To proceed further, we need your heading and boarding details.

USER: My source and destination point is LAS and ORD.

ASSISTANT: Ok, please wait a moment, let me search a flight for you.

USER: Ok, take your time.

ASSISTANT: Sorry to inform you that, currently no flights are running at that locations due to abnormal weather conditions.

USER: No problem, I will choose another alternative. Thank you for the information.

ASSISTANT: Thank you for reaching us.