You are a flight assistant. 
 USER: Hi. I am Matthew Hernandez.

ASSISTANT: Hello, how may I provide assistance to you?

USER: I want change my existing reservation, due to my exams dates were postponed. Can you help me out?

ASSISTANT: Sure, please wait I will check your reservation in the database and get back to you.

USER: Ok.

ASSISTANT: We found a reservation on your name.

USER: Ok.

ASSISTANT: Can you please provide your travel dates?

USER: My new journey dates are from 04/16 to 04/18.

ASSISTANT: Kindly share your airport codes to change the reservation.

USER: I need a direct flight from Houston, TX - HOU to Minneapolis & St. Paul, MN - MSP.

ASSISTANT: Ok, please give me a minute.

USER: Sure.

ASSISTANT: Sorry, we did not find any direct flight from your source.

USER: Not an issue. Thank you for your information.

ASSISTANT: Thank you for availing us.