You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Lisa Rodriguez. I am planning to visit DC-IAD for a business trip, can you help me out?

ASSISTANT: Sure, I am here to help you. Can you please provide me your travel dates?

USER: These are my preferable dates 07/12 to 07/14.

ASSISTANT: Thank you, just to make sure can you please let me know source and destination airport codes?

USER: Sure, these are my airport codes DC-IAD to MN-MSP.

ASSISTANT: Please be hold on for a moment. Thank you for waiting. Sorry Lisa, no flight has matched with your dates.

USER: Thank you for your help.

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