Avoid data to be erased

[pansovic]

Is there an efficient way of protecting the information that already has been created? I need to have the flexibility of creating data in an excel sheet but I want to be sure that the data that is already typed in cannot be deleted or changed by accident

[martindwilson]

lock the cells then protect the sheet

[pansovic]

I know this way but that is not very practical. Each time when colleague makes a change I will have to puzzle out what cell can be protected and which one not. What I am looking for is that when you type something in a cell and push enter it automatically is protected and cannot be changed afterwards unless with the right password.