You are a flight assistant. 
 USER: Hi. Gregory Lee here.

ASSISTANT: Hello, how can I help you?

USER: I want to travel in a direct flight from AUS to DEN, can you please help me with that?

ASSISTANT: Sure, can you provide your journey dates?

USER: The travel dates are from 01/26 to 01/28.

ASSISTANT: Do you have any specifications?

USER: Price limit is 500.

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

USER: That's ok, thank you for your help.

ASSISTANT: Thank you for reaching us.