offButton.src = “images/blueButton.gif” onButton.src = “images/redButton.gif” } ... such as moving the cursor over an image, JavaScript will catch it and do whatever you’ve asked it to do.

button1Red.src = “images/redButton1.gif” button1Blue.src = “images ... As always, only use this code if the browser you’re designing for supports image manipulation via JavaScript ...

Image() object in JavaScript and pass it the URL of the image you want preloaded. Say we have an image called heavyimagefile.jpg, which we want to ... imageObj.src=images[i]; }} ...

The image probably isn't loaded by that time. I mean, it's probably a couple milliseconds, if that, between when you assign that src and when you ask for the width and height.