var v = parseInt(navigator.appVersion);

isNetscape = navigator.appName.indexOf('Netscape') >= 0;
isExplorer = navigator.appName.indexOf('Explorer') >= 0;

function popupWindow(goLocation,w,h,name) {
ww = w; var wh = h;
positionCode = '';

if (v >= 4) {
   sw = screen.width; sh = screen.height;
   wbx = Math.round((sw-ww)/2); wby = Math.round((sh-wh)/2);
   if (isExplorer) positionCode = 'left='+wbx+',top='+wby+',';
   if (isNetscape) positionCode = 'screenX='+wbx+',screenY='+wby+',';
}

newWindow = window.open (goLocation,name,'width='+ww+',height='+wh+','+positionCode+'toolbar=1,location=0,directories=0,scrollbars=1,status=0,resizable=1');
return false;

if (isNetscape && v>=3) newWindow.focus();

return false;
}


function roll(imgName, imgSrc) {
 if (document.images) {
    document[imgName].src = imgSrc;
 }
}