function SetCookie (name, value) {  //设置名称为name,值为value的Cookie
        var argc = SetCookie.arguments.length;
        var argv = SetCookie.arguments;    
        var path = (argc > 3) ? argv[3] : null;
        var domain = (argc > 4) ? argv[4] : null;
        var secure = (argc > 5) ? argv[5] : false;
               
        document.cookie = name + "=" + value +
        ((path == null) ? "" : ("; path=" + path)) +  
        ((domain == null) ? "" : ("; domain=" + domain)) +    
       ((secure == true) ? "; secure" : "");        
}
function getCookieVal (offset) {       //取得项名称为offset的cookie值
    var endstr = document.cookie.indexOf (";", offset);  
    if (endstr == -1)
        endstr = document.cookie.length;  
        return unescape(document.cookie.substring(offset, endstr));
}
function GetCookie (name) {  //取得名称为name的cookie值
        var arg = name + "=";  
        var alen = arg.length;  
        var clen = document.cookie.length;  
        var i = 0;  
        while (i < clen) {    
        var j = i + alen;    
        if (document.cookie.substring(i, j) == arg)      
                return getCookieVal(j);    
                i = document.cookie.indexOf(" ", i) + 1;    
                if (i == 0) break;   
        }  
        return null;
}