gistfile1.js

 Selectfield.mainPage = SC.Page.design({

  mainPane: SC.MainPane.design({
    childViews: 'wrapper'.w(),
    
    wrapper: SC.View.design({
      childViews: 'content'.w(),
      
      content: SC.PanelPane.design({
        layout: { width: 360, height: 160, centerX: 0, centerY: 0 },
  	    
	contentView: SC.View.design({
          layout: { left: 17, right: 14, top: 76, height: 24 },
          childViews: 'sfield'.w(),

          sfield: SC.SelectView.design({
            layout: { width: 200, height: 24, right: 3,  centerY: 0 },

            items: [
              { name: 'For 3 Seconds', value: '3seconds' },
              { name: 'Until the browser is closed', value: 'closeBrowser' },
              { name: 'For 1 year', value: '1year' }
            ],

            itemTitleKey: 'name',
            itemValueKey: 'value'       
          })
        })
      })      
    })
  })
});