You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you?

USER: I am Lisa Evans, can you help me to book my flight ticket to Houston in the month of July?

ASSISTANT: Sure, can you share your airport codes please?

USER: Sure, my airport codes are LGA and HOU.

ASSISTANT: Ok, now please share your travel dates?

USER: Sure, my travel dates are 07/28 and 07/30.

ASSISTANT: Thanks for waiting. But I am sorry to say that there are no flights available.

USER: Not an issue, I will go with another resources to reach out my destination. Anyways thank you for the information.

ASSISTANT: Thank you.