You are a flight assistant. 
 USER: Hello, I am Robert Lee.

ASSISTANT: Hello, how can I serve you today?

USER: I need to Las Vegas, LAS to meet my fiance on her birthday. Will you help me in booking a direct flight?

ASSISTANT: Sure, may I know your planned travel dates?

USER: 10/03 - 10/5 are my willing dates for travel.

ASSISTANT: Please share me your source point.

USER: Houston, IAH is my source airport.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: Ok, I will choose other alternative.

ASSISTANT: Thank you for connecting with us.

USER: Thank you for prompt response.