If a field of DataForm is not going to be needed any more, delete it. To delete a field, first open DataForm.NET Manager. Choose a dataform in DataForm.NET List, the fields of that DataForm will be displayed in DataForm tab. Click "Delete" icon to remove field from DataForm. The distinction between "In use" and "Delete" is that if a field's "In use" property is not checked, it is disabled but its properites are still in DataForm, it can be enabled later. However, a fied is deleted, then all of its properties are gone.