Your screen shot is clipped such that we can't see all that's on the left, but what I can see suggests that the  are the wrong thing to use here as this is how you refer to a specific repetition in a repeating field (like an array index) and what you have inside the brackets is an expression that will return text.
And if you want the tableoccurrencename::fieldName reference for the currently active field, use: Get ( activeFieldTableName ) & "::" & Get ( ActiveFieldName )
But I don't see a reason in your original text why you would not just format a field to have a check box format instead of some more complex approach. A check box field can be set with a single value: 1 and resized to hide the 1 so that all is shown is the check box. Clicking it enters a 1. Clicking it again clears the 1.