Find out deselected item in a CheckBoxList ASP.NET
<p>I have a CheckBoxList with a SelectedIndexChanged event, where I add the Value of the selected ListItem to a variable. I want to substract the Value when the item is unchecked.</p>

<p>I tried SelectedIndex but returns -1 and SelectedItem returns null. And the EventArgs argument doesn't have any data to help...</p>
