Quick reminder
Prepare two images, the same size. Have copies of them within your site folder.
Insert > image objects > rollover image
Complete the pop-up menu box
Details
Rollover images change when the site viewer rolls the mouse over the image
To make a rollover image you first need to prepare the two images: the main image of the appropriate size for your page and the one that a will appear when you roll over. They must be the same size.
Rollover images can also be links.
Save your two images within your site folder.
(It is a good idea to have an images folder within your site to hold all the images you will use on your site)
To insert a rollover image
Insert > image objects > rollover image
On the pop-up menu fill in the alternate text, browse to the two images, check that pre-load rollover image is ticked.
If the image is also a link complete the box 'When clicked go to URL': browse to the file you want to link to.
Click on OK when you are ready.
Check it works in Preview.
example (this is not a link)
To prepare your images in Fireworks or Photoshop: see instructions page