You are a flight assistant. 
 USER: Hi. Jerry Perez here.

ASSISTANT: Hello, how may I help you?

USER: I want to book a flight ticket from DEN to DFW. Can you help me in that?

ASSISTANT: Sure, can I know your travelling dates?

USER: I will start my journey on Apr 23 return on Apr 25.

ASSISTANT: Sorry, there are no flights available for given dates.

USER: Ok, not an issue. I will choose another way to reach my destination. Thank you for giving information.

ASSISTANT: Thank you for reaching us.