espero esto sea lo que buscas
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Documento sin título</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<SCRIPT language=JavaScript>
<!--
function cambio(html){
vertochomorocho.innerHTML=html
}
//-->
</SCRIPT>
</head>
<body>
<table width="100%" border="0" cellspacing="4" cellpadding="4">
<tr>
<td width="34%"><img src="er3.gif" width="176" height="113" onmouseover="cambio('<b>Que trampa</b> se ve chido no?')" onmouseout="cambio('')"></td>
<td id="vertochomorocho" width="61%" rowspan="3"> </td>
<td width="5%"><img src="er3.gif" width="176" height="113" onmouseover="cambio('<b>Que trampa</b> se ve chido no?')" onmouseout="cambio('')"></td>
</tr>
<tr>
<td><img src="er3.gif" width="176" height="113" onmouseover="cambio('<b>Que trampa</b> se ve chido no?')" onmouseout="cambio('')"></td>
<td><img src="er3.gif" width="176" height="113" onmouseover="cambio('<b>Que trampa</b> se ve chido no?')" onmouseout="cambio('')"></td>
</tr>
<tr>
<td><img src="er3.gif" width="176" height="113" onmouseover="cambio('<b>Que trampa</b> se ve chido no?')" onmouseout="cambio('')"></td>
<td><img src="er3.gif" width="176" height="113" onmouseover="cambio('<b>Que trampa</b> se ve chido no?')" onmouseout="cambio('')"></td>
</tr>
</table>
</body>
</html>