This time, when the pop-up window opens, you are free to resize and scroll through the pop-up window as needed. Play Sound The next behavior in the Behaviors panel list is the Play Sound behavior. You can use this behavior as a way of playing sound files such as MP3, MIDI, and WAV in the browser window. Although popular browsers such as Internet Explorer can play most sound files directly within the browser, others such as Firefox and Netscape might require additional software like QuickTime to play the sound correctly. Netscape might even prompt you with a dialog, giving you the option of choosing the external audio player (QuickTime, Windows Media Player, iTunes, or RealAudio) to use. Playing audio in the browser is covered with much more detail in Chapter 18, "Adding Video and Audio," but for now let's explore this simple behavior. To work with the Play Sound behavior in your web page, follow these steps: 1. Place your cursor just after the previous Open Macromedia button and press Enter. 2. Insert a new Button form object by clicking the Button icon in the Forms category of the Insert bar. Give the new Button the text label Play Sound and change the Action to None to prevent the form from submitting or resetting. 3. With the Button selected, choose the Play Sound behavior from the Add (+) menu in the Behaviors panel. The Play Sound dialog appears. 4. In this dialog, browse to select a sound file. I've included a simple MIDI file in the Media folder of your project called PlaySound.mid. Choose it. 5. Click OK. 6. Ensure that the onClick event is attached to the Button. Save your work and test the result in the browser by choosing the Preview in Browser option from the Document bar (or by pressing F12). If you're using Internet Explorer, as I am, the sound is played without the need for additional software, directly in the browser, when you click the button. NOTE You should be aware that a Stop Sound behavior doesn't exist. Therefore the only way to stop the sound file from playing is to close the browser. If your users find your sound file annoying, they might be tempted to close the browser or navigate to a different page in an effort to avoid the sound.   Preload Images Typically added to image rollovers (covered later in this chapter) or when the page loads for the first time, the Preload Images Behavior can be used as a way of forcing the browser to load certain elements first, before other elements on the page are rendered. This behavior is beneficial when working with image rollovers (because they require two images to function correctly). As you'll see, when the page loads, a user sees the first image. As soon as their cursor rolls over the image, an event (typically the onMouseOver event) kicks in and calls necessary JavaScript code that changes the image to a second, usually different-colored image. On slower connections, the second image might appear as a broken image for a split second while it has a chance to load. To avoid showing a broken image icon (even for a split second), use the Preload Images behavior. This behavior forces the browser to load all images that are viewable on the page and to preload any images that might not be viewable on the page but must be queued for use in an effect such as a rollover. For the most part, this behavior is automatically added when working with rollovers in Dreamweaver. Set Nav Bar Image In Chapter 3, "Building a Web Page," we used the Navigation Bar dialog, available by selecting Insert, Image Objects, Navigation Bar, to build a fully functional navigation bar complete with images that changed color when the user's cursor rolled over them. Looking back, the dialog allowed us to add navigation bar elements, give the navigation bar element a unique name, add up,