private void ScenarioChk_MouseMove(object sender, MouseEventArgs e)
 {
     if (sttIndex != ScenarioChk.IndexFromPoint(e.Location))
     {
         GetSenToolTip();
     }
 }
        private void GetSenToolTip()
        {
            //foreach (var chk in ModelChk.Items)
            //{
            //    chk.Attributes.Add("title", "salam");
            //}

            sttIndex = ScenarioChk.IndexFromPoint(ScenarioChk.PointToClient(MousePosition));
            if (sttIndex > -1)
            {
                System.Drawing.Point p = PointToClient(MousePosition);
                toolTip1.ToolTipTitle = ScenarioChk.Items[sttIndex].ToString();
                toolTip1.SetToolTip(ScenarioChk, frmParent.SensTip[sttIndex].ToString());
            }
        }