Thank you, I already looked at that
Anyway it's not very clear.
I'm working with the MM_openBrWindow script that I'm using in Dreamweaver.
Usually if I want a simple pop-up image to appear "onload", I add the code to the <body> tag
<body onload="MM_openBrWindow('example.html','mywindow','width=500,height=500')">
</body>
I tried to add the floatbox class to the previous code, but nothing happens.
<body onload="MM_openBrWindow('example.html','mywindow','width=500,height=500', class="floatbox" data-fb-options="width:500 height:500", "autoStart:true")">
</body>
Anyway, this is the original MM_openBrWindow script ...
<script type="text/javascript">
<!--
function MM_openBrWindow(theURL,winName,features) { //v2.0
window.open(theURL,winName,features);
}
//-->
</script>