Update event of a checkbox

Hello,

maybe this is a very simple question, and I am blind.

I have 2 checkboxes that I am filling with values from a select of a database but let the checkbox empty / not showing any value at the start. I would like to update a data grid once the user selects one of those values.

But I do NOT want that this event is already triggered by the initial filling of the checkbox. Can this be avoided programmatically?

Many thanks

Christian