public delegate void setShowChartFormInvoke(Form myform);

        public void setShowChartForm(Form myform)
        {
            if (this.InvokeRequired)
            {
                setShowChartFormInvoke _setShowChartFormInvoke = new setShowChartFormInvoke(setShowChartForm);
                this.Invoke(_setShowChartFormInvoke, new object[] { myform });
            }
            else
            {
                myform.Show();
            }
        }

 this.myWindows.setShowChartForm(cf);