You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you today?

USER: I am Melissa Gonzalez, can you help me to book a flight from IAH to LAS?

ASSISTANT: Sure, I am happy to help you with that. May I know your journey dates, please?

USER: My travelling dates are 04/16 and 04/18.

ASSISTANT: Thank you for waiting. Sorry to tell you that, there are no flights available in your route as per your travel dates.

USER: No issues, thank you for your time.

ASSISTANT: You are welcome, thank you for approaching us.