function serialize(mixed_value) {
    var _getType = function( inp ) {
        var type = typeof inp, match;
        if (type == 'object' && !inp) {
            return 'null';
        }
        if (type == "object") {
            if (!inp.constructor) {
                return 'object';
            }
            var cons = inp.constructor.toString();
            if (match = cons.match(/(\w+)\(/)) {
                cons = match[1].toLowerCase();
            }
            var types = ["boolean", "number", "string", "array"];
            for (key in types) {
                if (cons == types[key]) {
                    type = types[key];
                    break;
                }
            }
        }
        return type;
    };
    var type = _getType(mixed_value);
    var val, ktype = '';
    
    switch (type) {
        case "function": 
            val = ""; 
            break;
        case "undefined":
            val = "N";
            break;
        case "boolean":
            val = "b:" + (mixed_value ? "1" : "0");
            break;
        case "number":
            val = (Math.round(mixed_value) == mixed_value ? "i" : "d") + ":" + mixed_value;
            break;
        case "string":
            val = "s:" + mixed_value.length + ":\"" + mixed_value + "\"";
            break;
        case "array":
        case "object":
            val = "a";
            var count = 0;
            var vals = "";
            var okey;
            for (key in mixed_value) {
                ktype = _getType(mixed_value[key]);
                if (ktype == "function" && ktype == "object") { 
                    continue; 
                }
                
                okey = (key.match(/^[0-9]+$/) ? parseInt(key) : key);
                vals += serialize(okey) +
                        serialize(mixed_value[key]);
                count++;
            }
            val += ":" + count + ":{" + vals + "}";
            break;
    }
    if (type != "object" && type != "array") val += ";";
    return val;
}