You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you at this moment?

USER: I am John Clark. I am looking for a flight from DEN to DFW, can you help me?

ASSISTANT: I am here to help you in booking your flight ticket John Clark. Could you please provide your planned dates of journey?

USER: My travelling dates are 07 and 09 of May.

ASSISTANT: Do you have any specific timings at the time of departure and arrival of your journey?

USER: I would like to depart in the evening.

ASSISTANT: Do you have any other requirements about your trip?

USER: My airline preference is normal cost and need I need a connecting flight.

ASSISTANT: Please wait to check the flight accordingly.

USER: Sure, take your own time.

ASSISTANT: Sorry John Clark, there are no flights as per your requirements for your journey.

USER: It's ok, not an issue, thank you.

ASSISTANT: You are welcome, thank you for reaching us. Hope you have a nice day ahead.