I have a datagrid with 3 checkboxes on each line.

Because only 1 checkbox can be checked on each line I am unchecking the other 2 checkboxes when a user checks a checkbox. This is pretty simple and is working fine. My problem is that I don't want a user to be able to uncheck a checkbox by clicking on it again after they already checked it. I would like to have any click on a checkbox to result in a check in that box. In the CellContentClick event I determine which checkbox was clicked and set the value of that cell to true. But it still leaves that cell unchecked if it was checked before the click. I am thinking that it actually resets the value of the cell after the CellContentclick event is completed which resets the value to false.
Any ideas? Thanks, Art