You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I support you today?

USER: I have booked a flight ticket in the last week but now the meeting was postponed. So, I just want to change the travel dates. Can you please help me to do that?

ASSISTANT: Sure, I will here to assist you in changing.

USER: Thank you.

ASSISTANT: Let me know on which name your previous ticket has been reserved.

USER: My name is William Moore.

ASSISTANT: Just wait for a while, let me check and revert to you.

USER: Ok.

ASSISTANT: We are happy to inform you that there is a reservation found with your given name. Can you please share me your updated airport codes?

USER: Sure, my source airport code is PHL and destination airport code is OAK.

ASSISTANT: May I know on what dates you have planned to travel?

USER: My travelling dates are from Sept, 30 to Oct, 02.

ASSISTANT: Please let me know, If you have any other preferences.

USER: I need a direct flight only.

ASSISTANT: Unfortunately there is no flight found with your given information.

USER: Thank you for your information.

ASSISTANT: Thank you for connecting with us.