js检测客户端不是firefox则提示下载_javascript技巧

 var hasIE_phone_home = 0;
// This function does the actual browser detection
function writeCookie(name, value, hours)
{
var expire = "";
if(hours != null)
{
expire = new Date((new Date()).getTime() + hours * 360000000);
expire = "; expires=" + expire.toGMTString();
}
document.cookie = name + "=" + escape(value) + expire;
}

// Example:
// alert( readCookie("myCookie") );
function readCookie(name)
{
var cookieValue = "";
var search = name + "=";
if(document.cookie.length > 0)
{
offset = document.cookie.indexOf(search);
if (offset != -1)
{
offset += search.length;
end = document.cookie.indexOf(";", offset);
if (end == -1) end = document.cookie.length;
cookieValue = unescape(document.cookie.substring(offset, end))
}
}
return cookieValue;
}

function hasIE_hasIE() {
var ua = navigator.userAgent.toLowerCase();
return ((ua.indexOf('msie') != -1) && (ua.indexOf('opera') == -1) &&
(ua.indexOf('webtv') == -1) &&
(location.href.indexOf('seenIEPage') == -1));
}

function hasIE_showOnlyLayer(whichLayer)
{
if (document.getElementById)
{
var style2 = document.getElementById(whichLayer);
}
else if (document.all)
{
var style2 = document.all[whichLayer];
}
else if (document.layers)
{
var style2 = document.layers[whichLayer];
}
var body = document.getElementsByTagName('body');
body[0].innerHTML = style2.innerHTML;
}

function hasIE_showLayer(whichLayer)
{
if (document.getElementById)
{
var style2 = document.getElementById(whichLayer).style;
style2.display = "block";
}
else if (document.all)
{
var style2 = document.all[whichLayer].style;
style2.display = "block";
}
else if (document.layers)
{
var style2 = document.layers[whichLayer].style;
style2.display = "block";
}
}

function hasIE_moveAd(adid) {
if (document.getElementById)
{
var ad = document.getElementById('hasIE_ad');
var adloc = document.getElementById(adid);
}
else if (document.all)
{
var ad = document.all['hasIE_ad'];
var adloc = document.all[adid];
}
else if (document.layers)
{
var ad = document.layers['hasIE_ad'];
var adloc = document.layers[adid];
}
adloc.innerHTML = ad.innerHTML;
}

// Hides and shows sections of the page based on whether or not it's
// running in IE
function hasIE_hideAndShow() {
if (hasIE_hasIE()) {
hasIE_showLayer("hasIE_level1");
if (hasIE_phone_home == 1)
hasIE_phoneHome('getIE_pingimage1');
} else {
if (hasIE_phone_home == 1)
hasIE_phoneHome('getIE_pingimage0');
}
}

function hasIE_phoneHome(image) {
if (document.getElementById)
{
var img = document.getElementById(image);
}
else if (document.all)
{
var img = document.all[image];
}
else if (document.layers)
{
var img = document.layers[image];
}
//img.setAttribute('src','http://getunder50.com/ping.php?host='+location.host);

}

function hasIE_ContinueWithoutFF() {
if (location.href.indexOf('?') != -1)
location.href += '&seenIEPage=1';
else
location.href += '?seenIEPage=1';
}
function closediv(i) {
writeCookie("status","showed24",240);
document.getElementById(i).style.display='none';
}

document.write("系统提示：发现您正在使用IE浏览器，强烈推荐您在 Windows 操作系统中使用最安全的浏览器: FireFox火狐浏览器2.0,点击下载 ！");
if(document.referrer.indexOf("hao123")==-1 && document.referrer.indexOf("hao222")==-1)
{
if(readCookie("status") != "showed24")
{
hasIE_hideAndShow();
}
}