partial void CalculateButton_TouchUpInside(UIButton sender)
        {
            /*             Calculate profits             */
            //get number of shares
            CheckEmpty();
            double entry     = Double.Parse(EntryTxtField.Text);
            double principal = Double.Parse(PrincipalTxtField.Text);
            double numShares = principal / entry;
            double exit      = Double.Parse(TargetTxtField.Text);
            double stop      = Double.Parse(StopLTxtField.Text);
            double profit    = Calculate.CalculateProfit(entry, exit, numShares);
            double ROI       = Calculate.CalculateROI(exit, entry);

            string rewardRatio = Calculate.CalculateRiskRewardRatio(entry, exit, stop, numShares);


            ResultLabel.Text = $"Profit: {Settings.Currency}{profit:0.00}, {rewardRatio}, ROI: {ROI:0}%";

            string info1 = $"Entry: {entry}, Target: {exit}, Stop: {stop}";

            CalculationHistory.AddData(info1, ResultLabel.Text);
        }
        partial void CalculateButton_TouchUpInside(UIButton sender)
        {
            CheckEmpty();

            /*             Calculate profits             */
            //get number of shares
            double entry     = Double.Parse(EntryTxtField.Text);
            double exit      = Double.Parse(TargetTxtField.Text);
            double principal = Double.Parse(PrincipalTxtField.Text);
            double numShares = principal / entry;
            double profit    = Calculate.CalculateProfit(entry, exit, numShares);


            // flip image for according to profit
            if (profit < 0)
            {
                TradeImage.Image = UIImage.FromBundle("Down-Market");
                ResultLabel.Text = $"Loss: {Settings.Currency}{profit:0.00}, " +
                                   $"ROI: {Calculate.CalculateROI(exit, entry):0}%";
            }
            else
            {
                TradeImage.Image = UIImage.FromBundle("Up-Market");
                ResultLabel.Text = $"Profit: {Settings.Currency}{profit:0.00}, " +
                                   $"ROI: {Calculate.CalculateROI(exit, entry):0}%";
            }



            /*           Add to history                 */

            // first param is cell title, second is subtitle
            string title = $"Principal: {principal}, Entry: {entry}, Exit: {exit}";

            CalculationHistory.AddData(title, ResultLabel.Text);
        }