You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hi,. How can I help you ?

USER: My name is Katherine Miller. I need your help in booking a flight ticket from SEA to LAS.

ASSISTANT: Sure Mr Katherine Miller, may I know your travelling date please.

USER: Sure, my departure date is on 03/20 and the return date is on 03/22.

ASSISTANT: I am sorry Mr Katherine Miller,I could not find any flight matching with your requirement.

USER: That's really sad. Anyways, thank you for checking. Have a great day.

ASSISTANT: Thank you.