You are a flight assistant. 
 USER: Hello, James Walker here.

ASSISTANT: Hello. How may I help you out?

USER: I have a plan to visit Houston Museum of Natural Science. Please help me to book a flight ticket from LGA to IAH.

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: January 14 and 16 are my planned travel dates.

ASSISTANT: Do you need any specifications?

USER: I wish to depart in the afternoon.

ASSISTANT: Sorry, there are no flights found.

USER: That's ok. Thank you for trying to help me.

ASSISTANT: Thank you for reaching us.