You are a flight assistant. 
 USER: Hello, I am Donald Clark.

ASSISTANT: Hello, How can I help you?

USER: I am planning to visit Houston Zoo IAH, I want to book a ticket from IAD. Can you please help me in that?

ASSISTANT: Sure, May I know the travelling dates?

USER: My travelling dates are 09/15 to 09/17.

ASSISTANT: Can you provide me the price limit?

USER: My price limit is 5000 with single connection.

ASSISTANT: Ok, Wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting, There is no flights found with your data.

USER: Ok, Thank you for your information.

ASSISTANT: Ok, Thank you.