You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I want to change my existing reservation which is done recently due to some problems, can you please help me in this?

ASSISTANT: Ok, may I know your name please?

USER: Sure, my name is Joseph Lopez.

ASSISTANT: Can you please tell me your trip dates?

USER: Ok, my planned dates of journey are from Apr, 12 to Apr, 14.

ASSISTANT: Can you please share your airport codes?

USER: Sure, my airport codes are from DFW to IAD.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thank you for waiting and we have found a flight in economy class with 1 connection in Delta airlines and the fare of your flight will be 300. Do you like me to proceed your booking with this flight?

USER: Ok, please book it.

ASSISTANT: Ok, your ticket is booked.

USER: Thank you for your help in reserving my ticket.

ASSISTANT: Most welcome.