Here's what I do, using Gofreeserve - check my link (on the left) to see it in action:
In File, Preferences:

And this is the script on the webpage, which refreshes every 30 seconds, even though the FTP upload is once a minute:
<IMG border=5 name=refresh src="RadarBoxScreenShot.gif"></P><P align=center>
<SCRIPT language=JavaScript type=text/javascript>
<!--
var t = 30 // interval in seconds
image = "RadarBoxScreenShot.gif" //name of the image
function Start() {
tmp = new Date();
tmp = "?"+tmp.getTime()
document.images["refresh"].src = image+tmp
setTimeout("Start()", t*1000)
}
Start();
// -->
</SCRIPT>
Hope that helps
Rod