You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Joshua Campbell. I am planning to travel from DTW to LAS.

ASSISTANT: Sure, help me with your trip dates.

USER: My date of travelling is on 06/28 to 06/30.

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

USER: That's ok. Thank you for your help.

ASSISTANT: Thank you for opting us.