You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Charles Lee.

ASSISTANT: Lee, how may I help you today?

USER: Can you help me searching flights on these routes SEA to DFW?

ASSISTANT: Sure, please provide your itinerary dates.

USER: My itinerary dates are 11/25 and 11/27.

ASSISTANT: Please wait for a moment to check for any available flight.

USER: Ok, I will wait for your reply.

ASSISTANT: Sorry, no flight is available for you. Do you want to travel on some other day?

USER: Oh! That's really sad to me, anyway no thanks. Thank you for your services.

ASSISTANT: Thank you for choosing us.