You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Mary Clark.

ASSISTANT: How can I assist you today?

USER: I would like to travel from HOU to IAD, can you please help me in booking flight ticket?

ASSISTANT: Sure, will you mention your travelling dates please?

USER: I prefer to travel on 07/05 and 07/07.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no flights found under your preferable details.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Welcome, have a great day.