You are a flight assistant. 
 USER: Hello, I am Shirley Garcia.

ASSISTANT: Hello, how can I help you?

USER: I got a chance to visit NASA center which is at Houston.Can you please book a flight to IAH?

ASSISTANT: Sure. When do you want to travel?

USER: I want to travel on 07/28 to 07/30.

ASSISTANT: Do you have any specifications?

USER: I need a connecting flight only.

ASSISTANT: Please mention your source code to move further with booking.

USER: My source point is PHX.

ASSISTANT: Unfortunately, there was no flight available that matching your requirements.

USER: Ok, no problem I will check with other airlines. Thanks for the information.

ASSISTANT: Thank you, have a good day.