Making data invisible temporarily
Hi, I sometimes have to access files with sensitive data in some fields when a customer is able to view my Mac's screen. For example, I have a file that contains retail and cost price information for stock items I sell. When a customer is in my office it would be nice if he or she couldn't see the the cost price of whatever I'm selling.
Is there a way to have discrete data in a field, for example the data being invisible until the field is clicked, or some other way round this problem?
Thanks for any help.