Postback Property in asp.net....

When you click the button, it causes a PostBack which will trigger the Page_Load event of your Asp.Net page.

You can check to see if it's a postback though, so you don't run code that should only run during an initial load.

e.g

private void Page_Load()
{
    if (!IsPostBack)
    {
        // Something that only happens in the first load
    }
}

Have a look here, which describes ViewState and postback processing

http://delphi.about.com/library/weekly/aa051705a.htm[^]