I have no results after pressing the button!

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Money_Management
{
    public partial class FMain : Form
    {
        public FMain()
        {
            InitializeComponent();
        }

        private void Btn_money_management_Click(object sender, EventArgs e)
        {
            string SoldeDuCompte = 
                 Text_Solde_Du_Compte.Text.Trim().ToString();
            string PositionAchat = Text_Position_Achat.Text.Trim().ToString();
            string PositionVente = Text_Stop_Loss.Text.Trim().ToString();
            string StopLoss = Text_Position_Achat.Text.Trim().ToString();
            string Risk = Text_Risk.Text.Trim().ToString();
            if (!string.IsNullOrEmpty(SoldeDuCompte) && 
                !string.IsNullOrEmpty(PositionAchat) && 
                !string.IsNullOrEmpty(PositionVente) && 
                !string.IsNullOrEmpty(StopLoss) && 
                !string.IsNullOrEmpty(Risk))
            {
                double DoubleSoldeDuCompte;
                double DoublePositionAchat;
                double DoublePositionVente;
                double DoubleStopLoss;
                double DoubleRisk;
                if (Double.TryParse(SoldeDuCompte, out DoubleSoldeDuCompte) 
                && Double.TryParse(PositionAchat, 
                out DoublePositionAchat) && 
                Double.TryParse(PositionVente, out DoublePositionVente) 
                && Double.TryParse(StopLoss, out DoubleStopLoss) 
                && Double.TryParse(Risk, out DoubleRisk))
                {
                    Double slpercent = 
                    (DoubleStopLoss - DoublePositionAchat) / DoublePositionAchat;
                    Double risk = DoubleRisk / 100;
                    Double ratio = risk / slpercent;
                    Double DoubleTaillePosition = DoubleSoldeDuCompte * ratio;

                    Label_Taille_Position.Text = " " + 
                            DoubleTaillePosition.ToString("#,#0.00 $");
                }
            }
        }
    }
}