Checkbox in list

I have a list and I want to add a checkbox on each entry to select some User for example to make a report.
Created a calculation field on that table and this is shown correctly, know I want to select some of it, but I’m not able to select or deselect the checkbox.

[attachment=0]12.01.png[/attachment]

I guess that, the framework dose disable me to do that.
What do I have to change or set that I’m able to edit this checkbox in the list?
Any Idea?