manu=navigator.appName;                 
vers=navigator.appVersion;              
if (manu.indexOf("Microsoft")>=0 && vers.indexOf("5")>=0)
                {location.href="ie/index_start.htm";} 
else if (manu.indexOf("Microsoft")>=0 && vers.indexOf("4")>=0)
                {location.href="ie/index_start.htm";}
else if (manu.indexOf("Netscape")>=0 && vers.indexOf("4")>=0)
                {location.href="nn/index_start.htm";}
else if (manu.indexOf("Netscape")>=0 && vers.indexOf("3")>=0)
                {location.href="nn/index_start.htm";}
else 
{location.href="nn/index_start.htm";}