function VideoPreviewPopUp()
{
    var url = "videopreview.html";
    var a="toolbar=no,location=no,directories=no,menubar=no,width=590,height=465"; 
    if (navigator.appName.indexOf("Microsoft")>=0) a+=",left=50,top=50";
    else a+=",screenX=50,screenY=50";
    if( floater != null )
            if( floater.closed == false )
               floater.close();
               var floater = null;
    floater=window.open(url,"videopreview",a);
    floater.focus();
}