Locking Objects

If you're certain that you want a particular object to remain where it is, you can use Object ‚ Lock Position, or z +L or Ctrl+L, to prevent the object from being moved. Generally, you'll want to lock repeating elements such as headers, footers, folios, and page numbers so that they're not accidentally moved. (Such repeating elements are usually placed on a master page; you can lock objects on master pages, too.) A locked object can't be moved whether you click and drag it with the mouse or change the values in the X and Y fields in the Control palette or Transform pane. Not only can you not move a locked object, you can't delete one, either. However, you can change other attributes of a locked object, including its stroke and fill.

To unlock an object, use Object ‚ Unlock Position, or Option+ z +L or Ctrl+Alt+L.

Cross-Reference ‚  

You can also lock entire layers , as described in Chapter 6.