Postback Causing Database Transactions To Replay

Hey,

 I hope someone can quickly tell me what I am obviously missing for this weird problem. 

To give a general picture, I have an ASP.net webpage that allows users to select values from several dropdown menus and click an add button which formats and concatenates the items together into a listbox. After the listbox has been populated the users have the option to save the items via a save button.


The save button parses each item in the listbox to basically de-code the concantenated values and subsequently inserts them into a table residing on a backend MSSQL 2005 database.

PROBLEM:

In the process of testing the application, I noted this strange behavior. If I use the webpage to insert the values, go to the table where the values are stored and delete the rows; Upon a refresh of the web page the same actions seem to be getting replayed and the items are again inserted into the table.

Naturally, what I'd really like would be for the page to refresh and show that the items aren't any longer there and not the other way around. 

If the code that performed the insert was residing in a component that was set for postback I'd expect this type of behavior but its in the Save buttons on_click event. I have tried practically everything in effort of targeting the problem but not having much luck with it.

Is this behavior practical and expected in ASP.net or has anyone ever heard of anything similar? I have never encountered this type of problem before and was hoping someone could provide some clues for resolving it. If more information is required I'd be happy to supply it. Hopefully, there's a simple explanation that I am simply unaware since I haven't experienced anything like this before.

Anybody got any ideas???

Thanks.