You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Margaret Martinez.

ASSISTANT: How may I help you?

USER: I want to travel from DEN to IAH. Can you help me in booking a flight ticket?

ASSISTANT: Sure, tell me your travel dates please?

USER: I want to travel in the flight on Mar 05 and Mar 07.

ASSISTANT: Please wait.

USER: I want to depart in afternoon time.

ASSISTANT: Thanks for waiting. But I am sorry to say that there are no flights available.

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

ASSISTANT: Thank you.