How to disable editing of previous list entries

I am using a list variable to create rosters for my area blocks. My building mappers are instructed to add the next number in the block listing sequence to create the next block roster. My mappers then enter each block roster and list all the buildings and their locations sequentially.

I find it is very easy for the mapper to accidentally delete a block list number thereby deleting the roster within which there are lots of buildings listed. Is there a way to disable the editing of sequentially created block numbers in a list to avoid the possibility of a block of information being deleted accidentally. The system issues a warning when the item in the list is being deleted. I have also place a warning in RED about this possibility, however, I fear this may not be enough to avoid the possibility of data loss.

Let me know if I can disable deletion of a list item after it has been created.

Best Regards

  1. The interviewer can modify any answers that she has entered.
  2. When changing a question that is a trigger for a roster she will get a warning from the program regarding what is about to happen. She can the decide whethet this change is desirable.