just name the images like this:

<img src="dog.gif" name="image1">
<img src="house.jpg" name="image2">

then you can say:

onMouseOver="document.image1.src='boat.jpg';document.image2.src='car.jpg'"





Or what I'd do is this:

<div id="pic1"></div>

then in a function you can say:

pic1.innerHTML="<a href='link.com'><img src='boat.jpg'></a>";

or

pic1.innerHTML="<font size=5 color='red'>whatever</font>";


There are lots of ways you can do this, but using the <div>'s in my opinion is the cleanest and most simple.