new SolidWorks Interop sldworks SldWorks can t open SolidWorks 2013

SF 2013-10-21

"new SolidWorks.Interop.sldworks.SldWorks()" can't open SolidWorks 2013

        private void button1_Click(object sender, EventArgs e)
        {
            SolidWorks.Interop.sldworks.SldWorks swApp;

            swApp = new SolidWorks.Interop.sldworks.SldWorks();
            swApp.Visible = true;
        }

Thanks.