Js 检测Ie版本 (转)

function getInternetExplorerVersion()
{
var rv = -1; // Return value assumes failure.
if (navigator.appName == ‘Microsoft Internet Explorer’)
{
var ua = navigator.userAgent;
var re = new RegExp(”MSIE ([0-9]{1,}[\.0-9]{0,})”);
if (re.exec(ua) != null)
rv = parseFloat( RegExp.$1 );
}
return rv;
}


function checkVersion()
{
var msg = “You’re not using Internet Explorer.”;
var ver = getInternetExplorerVersion();

if ( ver > -1 )
{
if ( ver >= 8.0 )
msg = “You’re using a recent copy of Internet Explorer.”
else
msg = “You should upgrade your copy of Internet Explorer.”;
}
alert( ver );
}