You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Joseph Miller.

ASSISTANT: Miller, how may I assist you?

USER: During to some issues, I just want to change an existing reservation.

ASSISTANT: Wait for a moment.

USER: My new reservation from TX-HOU to TX-HOU. My journey dates are 08/14 to 08/16. Make sure that price limit must be 1000 and connection limit must be 0.

ASSISTANT: Sorry, there is no reservation found with this name.

USER: Ok, thank you.