<img src="image1" />
img:hover{background:url(image2);}

<div id="fondImage"></div>

#fondImage { background-image : url(image1); width : x; height : y; }
#fondImage:hover { background-image : url(image2); }

WebD a écrit :
En javascript:
<img src="image1" onMouseOver="this.src='image2'"/>

<img src="image1" onmouseover="this.src='image2'" onmouseout="this.src='image1'" />

div {
    background-image : url(tonimage2);
    background-repeat : no-repeat;
}
div img {
    opacity : 0;
}