I am learning arrays. I have no idea what I am doing. This code is supposed to save the calculated totals and when the user clicks the exit button a message box pops up displaying the totals.

I'm trying to follow the examples in the book but it's not working. I have a build error down at the bottom and I underlined it.

"Error 1 A local variable named 'totals' cannot be declared in this scope because it would give a different meaning to 'totals', which is already used in a 'parent or current' scope to denote something else"

Can someone help me through this?


Code:
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;

namespace InvoiceTotal
{

    public partial class frmInvoiceTotal : Form
	{
		public frmInvoiceTotal()
		{
			InitializeComponent();
		}

        // TODO: declare class variables for array and list here

        decimal[] totals = new decimal[4];


        private void btnCalculate_Click(object sender, EventArgs e)
		{
            try
            {

                if (txtSubtotal.Text == "")
                {
                    MessageBox.Show(
                        "Subtotal is a required field.", "Entry Error");
                }
                else
                {
			        decimal subtotal = Decimal.Parse(txtSubtotal.Text);
                    if (subtotal > 0 && subtotal < 10000)
                    {
                        decimal discountPercent = 0m;
                        if (subtotal >= 500)
                            discountPercent = .2m;
                        else if (subtotal >= 250 & subtotal < 500)
                            discountPercent = .15m;
                        else if (subtotal >= 100 & subtotal < 250)
                            discountPercent = .1m;
                        decimal discountAmount = subtotal * discountPercent;
			            decimal invoiceTotal = subtotal - discountAmount;

                        discountAmount = Math.Round(discountAmount, 2);
                        invoiceTotal = Math.Round(invoiceTotal, 2);

                        txtDiscountPercent.Text = discountPercent.ToString("p1");
                        txtDiscountAmount.Text = discountAmount.ToString();
                        txtTotal.Text = invoiceTotal.ToString();

                        txtSubtotal.Focus();

                        for (int i = 0; i < totals.Length; i++)
                        {
                            totals[i] = i;
                        }


                    }
                    else
                    {
                        MessageBox.Show(
                            "Subtotal must be greater than 0 and less than 10,000.", 
                            "Entry Error");
                    }
                }
            }
            catch (FormatException)
            {
                MessageBox.Show(
                    "Please enter a valid number for the Subtotal field.", 
                    "Entry Error");
            }

            txtSubtotal.Focus();
        }

		private void btnExit_Click(object sender, EventArgs e)
		{
            // TODO: add code that displays dialog boxes here

            String[] totals = {};
            Array.Sort(totals);
            string message = "";
            foreach (string totals in totals)
                message += totals + "\n";
            MessageBox.Show(message, "Sorted Totals");

            this.Close();
		}

	}
}