How manage fields activation

Hi, I've a page with 50 fields (textbox, ddl, checkbox...)

I would to enable/disable the fields using specific condition ...
My fields are in specific groups

Group A: 20 fields (textbox, ddl, checkbox...)
Group B: 10 fields (textbox, ddl, checkbox...)
Group C: 15 fields (textbox, ddl, checkbox...)
...

When all fields of Group A are filled (and checked) each user can manage the fields of Group B and all fields of Group A are disabled... when all fields of groups B are filled, each user Can manage the fields of Group C and all fields of Group A and B area disabled
 
How Can I manage this problem?

Thanks


Grazie mille
 
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