Object.prototype.deep_clone = function(){
	eval("var tmp = " + this.toJSON());
	return tmp;
}
Object.prototype.toJSON = function(){
	var json = [];
	for(var i in this){
		if(!this.hasOwnProperty(i)) continue;
		//if(typeof this[i] == "function") continue;
		json.push(
			i.toJSON() + " : " +
			((this[i] != null) ? this[i].toJSON() : "null")
		)
	}
	return "{\n " + json.join(",\n ") + "\n}";
}
Object.prototype.toJSON = function(path, session){
	var json = [], key, index, p;
	path = path || "self";
	session = session || {path : [path], refs : [this]};
	for(var i in this){
		if(!this.hasOwnProperty(i)) continue;
		//if(typeof this[i] == "function") continue;
		key = i.toJSON();
		if((index = session.refs.indexOf(this[i])) != -1){
			json.push(key + " : " + session.path[index])
		}else{
			var p = path+"["+key+"]";
			session.refs.push(this[i])
			session.path.push(p);
			json.push(
				key + " : " +
				((this[i] != null) ? this[i].toJSON(p,session) : "null")
			)
		}
	}
	return "{\n " + json.join(",\n ") + "\n}";
}
Array.prototype.toJSON = function(){
	for(var i=0,json=[];i<this.length;i++)
		json[i] = (this[i] != null) ? this[i].toJSON() : "null";
	return "["+json.join(", ")+"]"
}

String.prototype.toJSON = function(){
	return '"' +
		this.replace(/(\\|\")/g,"\\$1")
		.replace(/\n|\r|\t/g,function(){
			var a = arguments[0];
			return  (a == '\n') ? '\\n':
					(a == '\r') ? '\\r':
					(a == '\t') ? '\\t': ""
		}) +
		'"'
}
Boolean.prototype.toJSON = function(){return this}
Function.prototype.toJSON = function(){return this}
Number.prototype.toJSON = function(){return this}
RegExp.prototype.toJSON = function(){return this}

// strict but slow
String.prototype.toJSON = function(){
	var tmp = this.split("");
	for(var i=0;i<tmp.length;i++){
		var c = tmp[i];
		(c >= ' ') ?
			(c == '\\') ? (tmp[i] = '\\\\'):
			(c == '"')  ? (tmp[i] = '\\"' ): 0 :
		(tmp[i] = 
			(c == '\n') ? '\\n' :
			(c == '\r') ? '\\r' :
			(c == '\t') ? '\\t' :
			(c == '\b') ? '\\b' :
			(c == '\f') ? '\\f' :
			(c = c.charCodeAt(),('\\u00' + ((c>15)?1:0)+(c%16)))
		)
	}
	return '"' + tmp.join("") + '"';
}