var win = Ti.UI.createWindow({
    backgroundColor: '#FFF'
});

var textField = Ti.UI.createTextField({
    hintText: 'Digite seu nome',
    top: 30,
    height: 40,
    width: 300,
    borderStyle: Ti.UI.INPUT_BORDERSTYLE_ROUNDED
});

win.add(textField);

var button = Ti.UI.createButton({
    title: 'clique aqui',
    top: 100,
    height: 50,
    width: 200,
});

button.addEventListener('click', function(e) {
    Ti.UI.createAlertDialog({
        message: 'Olá ' + textField.value
    }).show();
});

win.add(button);

win.open();