Text box: When a text box has focus, it contains a flashing cursor, as shown in Figure B-5. You can type text into a focused text box, and it is inserted at the location indicated by the cursor. To select text on either side of the cursor, hold down Shift+< or Shift+> (depending on the direction of the selection) until the desired text is selected. Then you can use the keyboard shortcuts that I list in Table B-3, earlier. Check box: When a check box has focused, its box is surrounded by a dotted, rectangular border, as shown in Figure B-5. You can select or (if it's currently selected) deselect a check box by pressing the spacebar. Radio button: A radio button is similar to a check box, but it is part of a group in which only one option can be selected. Thus, radio buttons are used for mutually exclusive options. For example, many online forms use two radio buttons to allow visitors to specify their gender. (The name radio buttons is a throwback to old car radios, from which large buttons protruded. Pressing one button popped the other buttons out.) When a radio button has focus, its circle is surrounded by a dotted border, as shown in Figure B-5. You can select an adjacent radio button in the group by pressing any of the four arrow keys depending on the direction in which the other button lies. To select a button in the group that's further away, just continue pressing the arrow key until you reach it.           Appendix C: Firefox Drag-and-Drop Reference Computer features are rarely intuitive, but drag-and-drop is one of those features that just feels right. It mimics the real-world experience of moving an item from one spot to another: Simply pick it up by pressing the mouse button, move it by moving the mouse, and put it down by releasing the mouse button over the new location. The Firefox philosophy is that anywhere drag-and-drop could work, it should work. This appendix outlines the possibilities, and I keep it short and sweet - just like drag-and-drop. Getting to Know Drag-and-Drop Most people are familiar with drag-and-drop from other programs, but in case you aren't, I walk through the process with a brief example. In the following steps, you load a Web page by dragging a link: Navigate to a Web site normally. Google (http://www.google.com) or Wikipedia (http://en.wikipedia.org) would be good for practice. Drag a link by moving the mouse pointer over it and holding down the left mouse button. Do not release the button. Move the mouse pointer to the Go button that sits to the right of the Location Bar. Notice that as you move the mouse pointer over the page, the arrow turns into a "no" sign (the circle with a line through it). This sign means that you can't drop the link at that spot. When the pointer reaches the Go button, it returns to being an arrow and shows a tiny box to indicate that you can drop on the Go button. Release the mouse button. Firefox loads the page that the link led to. Of course, this is a rather silly example, because you could simply have clicked the link to load the page. However, I want to start with something that has no side effects so you can get the hang of it.