Access Object-C properties in JavaScript example

obect-c-javascript.js

ObjC.import("Cocoa"); 
var styleMask = $.NSTitledWindowMask | $.NSClosableWindowMask | $.NSMiniaturizableWindowMask; 
var windowHeight = 350; 
var windowWidth = 550; 
var window = $.NSWindow.alloc.initWithContentRectStyleMaskBackingDefer( $.NSMakeRect(0, 0, windowWidth, windowHeight), styleMask, $.NSBackingStoreBuffered, false ); 

var label = $.NSTextField.alloc.initWithFrame($.NSMakeRect(25, (windowHeight - 40), 200, 24)); 
label.stringValue = "Label:"; 
label.drawsBackground = false; 
label.editable = false; 
label.bezeled = false; 
label.selectable = true; 

var textField = $.NSTextField.alloc.initWithFrame($.NSMakeRect(25, (windowHeight - 60), 205, 24));

window.contentView.addSubview(label); 
window.contentView.addSubview(textField); 

window.center; 
window.title = "Check"; 
window.makeKeyAndOrderFront(window);