browser_name = navigator.appName;
browser_version = parseFloat(navigator.appVersion);

if (browser_name == "Netscape" && browser_version >= 3.0) { roll = 'true'; }
else if (browser_name == "Microsoft Internet Explorer" && browser_version >= 3.0) { roll = 'true'; }
else { roll = 'false'; }

function over(img,ref) { if (roll == 'true') { document.images[img].src = eval(img+'.src'); } }
function out(img,ref)  { if (roll == 'true') { document.images[img].src = ref; } }

function trim(str) {
  return str.replace(/^\s*/,'').replace(/\s*$/,'');
}