如何添加分数和总分

" 当用户单击"添加您的分数"菜单项时，将每种饮料的分数添加到饮料的总数中，清除文本框，然后重置焦点。

我试图弄清楚如何添加上面引用的内容。我想我想太多了，让它比实际情况更难。

以下是我到目前为止所做的：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;
namespace Lab6
{      
public partial class NewTester : Form
{
    private int AppleAde;
    private decimal TotalScore;
    private string Winner_Name = ""; 
    int PrunePunch_Score;
    int Total_Num_Of_Tasters;
    decimal Average_Rating_Of_Each_Drink;
    //private decimal Total_Score;
    public NewTester()
    {
        Thread t = new Thread(new ThreadStart(SplashStart));
        t.Start();
        Thread.Sleep(5000);
        InitializeComponent();
        t.Abort();
    }
    public void SplashStart() {
    Application.Run(new Form2());
    }
    private void Form1_Load(object sender, EventArgs e)
    {
    }
    private void exitToolStripMenuItem_Click(object sender, EventArgs e)
    {
        this.Close(); 
    }
    private void aboutToolStripMenuItem_Click(object sender, EventArgs e)
    {
        MessageBox.Show("Lab6 by J Soto 'nThis lab was started on 10/9/13","About Lab 6",MessageBoxButtons.OK);
    }
    private void addYourScoresToolStripMenuItem_Click(object sender, EventArgs e)
    {   // Vars for text box values...
        PrunePunch_Score = Convert.ToInt32(PrunePunchTextBox.Text);
        AppleAde = Convert.ToInt32(AppleAdeTextBox.Text);

        //...
        if ((PrunePunch_Score <= 10) && (PrunePunch_Score >= 0))
            Convert.ToInt32(PrunePunchTextBox.Text);

        else
            MessageBox.Show("Please enter a number between 0 and 10","Prune Punch");
        if ((AppleAde <= 10) && (PrunePunch_Score >= 0))
            Convert.ToInt32(AppleAdeTextBox.Text);
        else
            MessageBox.Show("Please enter a number betwen 0 and 10","Apple Ade");
       //...

    }
    private void PrunePunchTextBox_TextChanged(object sender, EventArgs e)
    {
        PrunePunch_Score = Convert.ToInt32(PrunePunchTextBox.Text); 
    }
    private void AppleAdeTextBox_TextChanged(object sender, EventArgs e)
    {
        AppleAde = Convert.ToInt32(AppleAdeTextBox.Text);
    }
    private void summaryToolStripMenuItem_Click(object sender, EventArgs e)
    {
        string Summary;
       // Summary= "Winner:"+ Winner_Name "Total Number of Taste Testers:" + Total_Num_Of_Tasters "Average rating for each drink:" + Average_Rating_Of_Each_Drink; 

    }
}

}