var bName = navigator.appName;
var bVer  = navigator.appVersion;
var IE6   = (navigator.appVersion.indexOf('MSIE 6.0') >= 0 ) ? 1 : 0;
var IE7   = (navigator.appVersion.indexOf('MSIE 7.0') >= 0 ) ? 1 : 0;

//if((bName.indexOf('Microsoft Internet Explorer') > 0 && IE7 == 0 ) || (bName == 'Netscape' && parseInt(bVer) < 5) ) 
//  window.location.replace("browser.html")