private void rdoWhile_CheckedChanged(object sender, EventArgs e)
        {

           

            int x = 1;
            int total = 0;

            while (x < 10)
            {
                total += x;
                lbAnswer.Items.Add(x);
                
                x++;

            }
            lbAnswer.Items.Add("     ");
            lbAnswer.Items.Add("Total ====> " + total);
            
        }
        //_____________________________________________________________________________________

        private void rdoDoWhile_CheckedChanged(object sender, EventArgs e)
        {
           
            int x = 1;
            int total = 0;

            do
            {
                lbAnswer.Items.Add(x);
                total += x;
                x++;

            }
            while (x <= 15);

            lbAnswer.Items.Add("     ");
            lbAnswer.Items.Add("Total ====> " + total);
           
        
        }