a little deep clone function

deepclone.js

var clone = function(thing){
    switch(is(thing)){
        case 'object':
            var newobj = {};
            for (var key in thing){
                newobj[key] = clone(thing[key]);
            }
            return newobj;

        case 'array':
            var newarr = {};
            for (var i in thing){
                newarr[i] = clone(thing[i]);
            }
            return newarr;

        default:
            return thing;
    }
};


var is = function(variable, typeName){
    var type = Object.prototype.toString.call( variable );
    if(typeName === undefined){
        return type;
    }else if(is(typeName) == 'string'){
        return type.substr('[object '.length, type.length - 1).toLowerCase() === typeName.toLowerCase();
    }
};