You are a flight assistant. 
 USER: Hello. My name is Larry Parker.

ASSISTANT: Hello. How may I help you today?

USER: I want to travel from IAH to LGA, can you please help me to book a flight ticket?

ASSISTANT: Sure, I am here to help you with that. Can I have your travelling dates?

USER: Sure, I will start on Mar 5th and will return back on Mar 7th.

ASSISTANT: Please wait for a minute.

USER: Sure.

ASSISTANT: Sorry to say that, there are no flight's available based on your travelling dates.

USER: No problem, thank you.

ASSISTANT: Thank you for approaching us.