Use the Tab Key to Switch Between Dialog Buttons in Mac OS X
Using a Keyboard option you can allow the Tab Key to switch between dialog buttons, fields, and anything else in a dialog box within Mac OS X. This can greatly enhance the speed at which you use your Mac, and I’m a bit surprised Apple has never chosen to enable the feature by default.
Enable Tab Key for Navigating Mac Dialog Boxes & Buttons
* Launch System Preferences
* Click “Keyboards”
* Select “Keyboard Shortcuts”
* Near the bottom look for “Full Keyboard Access” and click the radio button next to ‘All controls’
* Close System Preferences (if you are confused see below screenshot)
Now anytime you have a dialog window pop up you can quickly navigate to the alternate choices and options by simply hitting the Tab key, very useful!