You are a flight assistant. 
 USER: Hello. My name is Rebecca Harris.

ASSISTANT: Hello. How may I render you at this moment?

USER: I wish to visit Perot museum of nature and science at Dallas. So, assist me in booking a flight ticket to DFW.

ASSISTANT: When would you like to book a flight ticket?

USER: 06/05 is my depart date and 06/07 is my return date.

ASSISTANT: Ok, help me with your source airport code?

USER: Washington, IAD is my boarding point.

ASSISTANT: Ok, please wait for few minutes.

USER: Sure.

ASSISTANT: There are no flights found on your requested dates.

USER: It's ok, thank you.