Here is a attached Door Frame family with multiple choice of with or without side winows & ventilators. Geometry of window & vent can be set to zero but the problem is with grills fitted in Win & Vents. The grills cant be set to zero length so a limit has been set.
The problem is with visibility of Lt & Rt. vent grills. I need to set them invisible if their width & Ht do not follow a certain vlue.
Grills are visible inspite my window & vent is set to zero.
So for this reasons I need to set the visibility of Lt & Rt vent Grills but formulas are not working.