private variables in javascript

 (function(window){
     //private variables
    var name = "test";
   
    var pieAGSI = function(){};

    // get variable
    pieAGSI.prototype.getName = function(){
        return name;
    };
   
    // update variable
    pieAGSI.prototype.setName = function(str){
        name = str;
    };
   
    window.pieAGSI = pieAGSI;
   
})(window);

// test
var test = new pieAGSI();
document.write('<br>test.getName(): ' + test.getName()+"<br>");