Questo è il codice che ho inserito!

<script language="JavaScript" type="text/JavaScript">
<!--
function hidePlot() {
if (document.getElementById)
{
// this is the way the standards work
var style2 = document.getElementById('plot').style;
style2.display = style2.display? "":"block";
}
else if (document.all)
{
// this is the way old msie versions work
var style2 = document.all['plot'].style;
style2.display = style2.display? "":"block";
}
else if (document.layers)
{
// this is the way nn4 works
var style2 = document.layers['plot'].style;
style2.display = style2.display? "":"block";
}
}
//-->
</script>

<div id="plot" style="display:none;">

</div>