OnMouseOver

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>

<script type="text/javascript">
var images = new Array("http://www.marchechampetre.ca/chicken.jpg","http://www.fwallpapers.net","http://www.fwallpapers.net");
var position = 1;
var len  = images.length;
function changerImage(tag) 
{ 
    tag.src = images[position % len]; 
    ++position;
    tag.mouseover = null; 
    //attendre deux seconde pour reactiver la fonction
    setTimeout( function(){tag.mouseout = function(){remetreLaFunctionInitial(tag);}; } , 5000);
} 


var defile = true;
function changerImageParSecond(tag, secondes) 
{ 
    tag.src = images[position % len]; 
    ++position;
    tag.onmouseout = function(){defile = false;};
    if(defile)
    tm = setTimeout(  function(){changerImageParSecond(tag, secondes); } , 1000*secondes);
} 


function remetreLaFunctionInitial(tag) 
{ 
   tag.onmouseout = null; 
   tag.onmouseover = function(){changerImage(tag);}; 
} 

</script>
</head>
<body>
   normal
  <img id="imgid" width="200" height="200" src="http://bilder.gebrauchtwagen.at/fahrzeug_bilder/55/55665/t_1338091_21293548462.JPG" onmouseover="changerImage(this);"/>
  
  automatique
  <img id="imgid" width="200" height="200" src="http://bilder.gebrauchtwagen.at/fahrzeug_bilder/55/55665/t_1338091_21293548462.JPG" onmouseover="changerImageParSecond(this,3);"/>
</body>
</html>

<html>
  <head>
    <script type="text/javascript">
      function changeImage(id, src)
      {
        var img = document.getElementById(id);
        img.src = src;
      }
    </script>
  </head>
  <body>
    <img id="image1" src="image1.jpg" onmouseover="changeImage('image2', 'image3.jpg')" onmouseout="changeImage('image2', 'image2.jpg')"/>
    <img id="image2" src="image2.jpg" />
  </body>
</html>

 onmouseover="changerImage(this)"

function changerImage(tag) 
{ 
    tag.src = "image2"; 
    tag.mouseover = null; 
    tag.mouseout = function(){remetreLaFunctionInitial(tag);}; 
} 

function remetreLaFunctionInitial(tag) 
{ 
   tag.onmouseout = null; 
   tag.onmouseover = function(){changerImage(tag);}; 
}