EXERCISE: Look at the img tags in the html, and write two functions.
The first function is called preloadImages(); it should be called by the onload event and load the three different versions of the full-size shirt image.
The second funciton is called swapImg() and it should be called by the onmouseover event of each of the three thumbnails.
Write the code so that when you hover over a thumbnail, the main image (id="img1") will change it's src property to match the color of the thumbnail.
Finally, in swapImg(), after the code that changes the full-size shirt image, write code that will set the border attribute equal to 1 for the thumbnail that got
'rolled over'.




EXTRA CREDIT: right code in swapImg() so that only the thumbnail image that is being hovered over has the border.
Note: there are different ways you can do this!!!