Все разобрался. Еще раз спасибо.
Нашел еще один вариант:
<html>
<head>
<script type="text/javascript">
function zam1() {
new_p = "<img src='big1.png' height='200'>";
document.getElementById('big1').innerHTML=new_p;
}
function zam2() {
new_p = "<img src='big2.png' height='200'>";
document.getElementById('big1').innerHTML=new_p;
}
function zam3() {
new_p = "<img src='big3.png' height='200'>";
document.getElementById('big1').innerHTML=new_p;
}
function zam4() {
new_p = "<img src='big4.png' height='200'>";
document.getElementById('big2').innerHTML=new_p;
}
function zam5() {
new_p = "<img src='big5.png' height='200'>";
document.getElementById('big2').innerHTML=new_p;
}
function zam6() {
new_p = "<img src='big6.png' height='200'>";
document.getElementById('big2').innerHTML=new_p;
}
</script>
</head>
<body>
<div id="big1"><img src="big1.png" height="200"></div>
<img src="small1.png" onMouseOver="zam1()">
<img src="small2.png" onMouseOver="zam2()">
<img src="small3.png" onMouseOver="zam3()">
<div id="big2"><img src="big4.png" height="200"></div>
<img src="small4.png" onMouseOver="zam4()">
<img src="small5.png" onMouseOver="zam5()">
<img src="small6.png" onMouseOver="zam6()">
</body>
</html>