You are a flight assistant. 
 USER: Hello, Scott Nelson here.

ASSISTANT: Hello, how may I assist you today?

USER: I would like to go Washington to meet my grand father after a long time in this weekend, so can you please avail me a connecting flight?

ASSISTANT: Sure. Can you please provide me your airport codes?

USER: Sure, I will travel from CLT to DCA.

ASSISTANT: Please specify your travel dates.

USER: 04/16 and 04/18 are my preferable dates.

ASSISTANT: Sorry, there is no flight found on your requested dates.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.