How to assign multple icons to different nodes and sub-nodes...?

 static ImageList imageList;
        public static ImageList ImageList
        {
            get
            {
                if (imageList == null)
                {
                    imageList = new ImageList();
                    imageList.Images.Add(Image.FromFile("database.png"));
                    imageList.Images.Add(Image.FromFile("sql.jpg"));
                   // imageList.Images.Add(Image.FromFile("col.jpg"));
                }
                return imageList;
            }
        }
 private void Form1_Load(object sender, EventArgs e)
        {
            treeView1.ImageList = ImageList;
            treeView1.Nodes[0].ImageKey ="database.png";
            treeView1.Nodes[0].SelectedImageKey = "database.png";
            treeView1.Nodes[1].ImageKey = "sql.jpg";
            treeView1.Nodes[1].SelectedImageKey = "sql.jpg";

            treeView1.Nodes[0].Nodes[0].ImageKey = "Table.jpg";
            treeView1.Nodes[0].Nodes[0].SelectedImageKey = "Table.jpg";
            treeView1.Nodes[0].Nodes[1].Nodes[0].ImageKey = "col.jpg";
            treeView1.Nodes[0].Nodes[1].Nodes[0].SelectedImageKey = "col.jpg";
        }
Problem:-
Only single image is showing by every node of the treeView control....