viewing images in a picturebox P2

[bigjoe11a]

I have some code that some one help me with. Its just that theres a new part that I added to my software. And the code I have doesn't want to work right.

What I'm trying to do is, I have whats called a Terrain. The Terrain has 3 parts (Images) A color image. B&W image and a 3D image.
C = Color
D = 3d
H = B&W

I have a 3 buttons that says C H D. What I want to do is scroll threw the color images and when I come to a Terrain that I want to view the D and H images. I just click the D and H buttons.
The problem is that they roll back one (1) or two (2) images, So you not really viewing the right image.

The code I have is below. I tried to explain this as best as I can.
VC# 2008 in NET 3.5.

I have a textbox1 that displays the file name. with a C D H buttons and a Next and Prev Bottons on one (1) form.

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

        public List<string> list;
        public int count;
        public int index = 0;

        private void Terrain_Load(object sender, EventArgs e)
        {
            string[] fl = Directory.GetFiles(@"images\ViewC\");
            list = new List<string>();
            foreach (string str in fl)
            {
                if (str.EndsWith(".jpg"))
                {
                    list.Add(str);
                }
            }
            count = list.Count;
            if (count != 0)
            {
               this.pictureBox1.ImageLocation = list[0];
              index = 0;
               textBox1.Text = list[0];
           }
        }

        private void btnC_Click(object sender, EventArgs e)
        {
            string[] fl = Directory.GetFiles(@"images\ViewC\");
            list = new List<string>();
            foreach (string str in fl)
            {
                if (str.EndsWith(".jpg"))
                {
                    list.Add(str);
                }
            }
            count = list.Count;
            if (count != 0)
            {
                this.pictureBox1.ImageLocation = list[0];
                index = 0;
            }
        }

        private void btnNext_Click(object sender, EventArgs e)
        {
            if (count > 1)
            {
                if (index == 0)
                {
                    index = count - 1;
                }
                else
                {
                    index--;
                }

            }

            this.pictureBox1.ImageLocation = list[index];
            //textBox1.Text = 
            textBox1.Text = list[index];
        }

        private void btnPrev_Click(object sender, EventArgs e)
        {
            if (count > 1)
            {
                if (index == count - 1)
                {
                    index = 0;
                }
                else
                {
                    index++;
                }
            }


            this.pictureBox1.ImageLocation = list[index];
            //textBox1.Text = 
            textBox1.Text = list[index];
        }

        private void btnD_Click(object sender, EventArgs e)
        {
            string[] fl = Directory.GetFiles(@"images\ViewD\");
            list = new List<string>();
            foreach (string str in fl)
            {
                if (str.EndsWith(".jpg"))
                {
                    list.Add(str);
                }
            }
            count = list.Count;
            if (count != 0)
            {
                this.pictureBox1.ImageLocation = list[0];
                index = 0;
            }

        }

        private void btnH_Click(object sender, EventArgs e)
        {
            string[] fl = Directory.GetFiles(@"images\ViewH\");
            list = new List<string>();
            foreach (string str in fl)
            {
                if (str.EndsWith(".jpg"))
                {
                    list.Add(str);
                }
            }
            count = list.Count;
            if (count != 0)
            {
                this.pictureBox1.ImageLocation = list[0];
                index = 0;
            }
        }

        private void btnExit_Click(object sender, EventArgs e)
        {
            this.Close();
        }