Few examples of reading cookie values

function GetCookieValue(cookieName) {
    var cookies = document.cookie.split(';');
    for (var i = 0; i < cookies.length; i++) {
        var cookie = cookies[i];
        while (cookie.charAt(0) === ' ')
            cookie = cookie.substring(1, cookie.length);
        if (cookie.indexOf(cookieName) === 0) {
            return cookie.substring(cookieName.length + 1, cookie.length);
        }
    }
    return null;
}

function getCookie(name) {
    var cookies = document.cookie.split('; ');
    for(i=0, n=cookies.length; i<n; i++) {
        if(cookies[i].indexOf(name) != -1) {
            var target = cookies[i].split('=');
        }
    }
    if(target) {
        return target[1];
    }else{
        return '';
    }
}

function getCookie(name) {
    var matches = document.cookie.match(new RegExp(
        "(?:^|; )" + name.replace(/([\.$?*|{}\(\)\[\]\\\/\+^])/g, '\\$1') + "=([^;]*)"
    ));
    return matches ? decodeURIComponent(matches[1]) : undefined
}

function getCookie(key) {
    var keyValue = document.cookie.match('(^|;) ?' + key + '=([^;]*)(;|$)');
    return keyValue ? keyValue[2] : null;
}

function getCookie(name) {
    var value = "; " + document.cookie;
    var parts = value.split("; " + name + "=");
    if (parts.length == 2) return parts.pop().split(";").shift();
}

function getCookie(name) {
     var cname = name + "=";
    var dc = document.cookie;
    if ( dc.length > 0 ) {
       begin = dc.indexOf(cname);
       if ( begin != -1 ) {
             begin += cname.length;
          end = dc.indexOf(";",begin);
          if (end == -1) end = dc.length;
          return unescape(dc.substring(begin, end) );
       }
    }
}

function GetCookie(name)
{
    var cookies=document.cookie.split(';');
    for(var i=0;i<cookies.length;i++)
    {
        var parts=cookies[i].split('=');
        if(name==parts[0].replace(/\s/g,''))
            return unescape(parts[1])
    }
    //return undefined..
}