Use the preload image behavior to load images that are temporarily not displayed on the page into the browser cache. When you use an object that contains more images, you can download the pictures you use to the browser cache to improve the speed and effect of the display.
Dreamweaver pre-loading image behavior
1. Open the document and select an object.
2. Open the Behavior panel.
3. Click the "Add behavior (+)" button and select the "Pre-load Image" command in the pop-up drop-down menu. As shown in the following illustration:
4. Open the Pre-loading Image dialog box, as shown in the following illustration:
Enter the URL of the image file in the Image source text box, or click the Browse button to select the image file you want to preload.
Click the (+) button at the top to add a file vacancy to the pre-loading image.
Add the URL address of the new image file in the image source file text box.
Repeatedly click the "(+)" button and the "Browse" button to add more image files.
You can delete an image file by clicking on an image file in pre-loading image and clicking on the "(-)" button at the top.
5. Click "OK" button.
6. See if the attached event is a required event. If it is not the event you want, you can change the event.
7. See if the behavior parameters are appropriate. You can also modify the behavior parameters if they are not appropriate.
Second, tips
If you select the Preload image option in the Swap Image dialog box, the swap image action will automatically preload the highlighted image, so you no longer need to manually add preload images when you use swap images.