Limiting scroll area

Hello to everyone.

For Excel 2003.
I have a workbook that i need to give to other users. In some worksheets i need to limit the area users can access so i right click on the worksheet tab, select View Code and enter the area users can use on the Scroll Area property. It works when i'm using the workbook. However, when users open the workbook, this definition is no longer active and they can access all the worksheet. Am i doing something wrong?

Thanks to all in advance.

Octavio

Thanks a lot R