Comparing existing and modified values of chekbox column in datagrid
<p>I have datagrid which shows activity name and a checkbox column. User checks the checkbox if he/she wants to select that activity and presses submit button to successfully add it.</p>

<p>If user wants to un-check the checked checkboxes i have to make certain validation to check whether that activity is currently associated with any other thing or not.</p>

<p>How can i do that?</p>
