The html code of this page between tags <body> .... </body> is

<body onLoad="MM_preloadImages('../../../images/16225265-smettere-di-icona.jpg')">

<div style="margin:0 auto;">
<div id="bottone" ><a href="rollover_img.htm" onMouseOut="MM_swapImgRestore()"
onMouseOver="MM_swapImage('Image1','','../../../images/16225265-smettere-di-icona.jpg',1)">
<img src="../../../images/16225351-giocare-icona.jpg" alt="" width="450" height="450" id="Image1"></a>
</div></div>

You can set a button into DIVs tags or into a table's cell, as you want, into the page that you want. This is a sample with the 2 big images, that are reachable going back to the root directory, that is

NOTE: we can put more swapping images that using the same script into the same page by changing the name Image1 to other buttons