XNA Alpha Textures

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 Microsoft.Xna.Framework.Graphics;
using LibBadTactics;

namespace MapEditor {
    public partial class frmMain : Form {
        public frmMain() {
            InitializeComponent();
            //texture1 = Texture2D.FromFile(scoper2DRenderer1.GraphicsDevice, "Terrain/rock.bmp");
            ////texture2 = Texture2D.FromFile(scoper2DRenderer1.GraphicsDevice, "Terrain/sand.bmp");
            //texture2 = Texture2D.FromFile(scoper2DRenderer1.GraphicsDevice, "Terrain/snow.bmp");

            //texture3 = TextureBuilder.FromFileWithAlpha(scoper2DRenderer1.GraphicsDevice, "Terrain/rock.bmp", "Terrain/test.bmp");
            ////incercam sa modificam alpha la texturi
            ////Texture2D tex = new Texture2D(scoper2DRenderer1.GraphicsDevice, 512, 512,64,TextureUsage.Linear,SurfaceFormat.Rgba32);
            map = new Scoper2DMap(this.scoperMain, "Terrain/test.bmp", 6120, 6120);
            mapPreview = new Scoper2DMap(this.scoperPreview, "Terrain/test.bmp", 6120, 6120);
        }
        Scoper2DMap map;
        Scoper2DMap mapPreview;
        int x;
        int y;
        private void scoper2DRenderer1_Draw(int TickCount) {
            scoperMain.GraphicsDevice.Clear(Microsoft.Xna.Framework.Graphics.Color.White);
            map.Render(x, y);
            x += dx;
            y += dy;
            if (x < 0) x = 0;
            if (y < 0) y = 0;
            if (x > 4500) x = 4500;
            if (y > 4500) y = 4500;
        }
        int dx;
        int dy;
        private void Form1_KeyDown(object sender, KeyEventArgs e) {
            if (e.KeyCode == Keys.Up) {
                dy = -10;
            }
            if (e.KeyCode == Keys.Down) {
                dy = 10;
            }
            if (e.KeyCode == Keys.Left) {
                dx = -10;
            }
            if (e.KeyCode == Keys.Right) {
                dx = 10;
            }
        }

        private void Form1_KeyUp(object sender, KeyEventArgs e) {
            if (e.KeyCode == Keys.Up) {
                dy = -0;
            }
            if (e.KeyCode == Keys.Down) {
                dy = 0;
            }
            if (e.KeyCode == Keys.Left) {
                dx = 0;
            }
            if (e.KeyCode == Keys.Right) {
                dx = 0;
            }

        }

        private void Form1_MouseDown(object sender, MouseEventArgs e) {
            if (e.Button == MouseButtons.Left) {
                if (e.X < this.scoperMain.Width / 4) {
                    dx = -25;
                } else if (e.X > this.scoperMain.Width * 3 / 4) {
                    dx = 25;
                } else {
                    dx = 0;
                }
                if (e.Y < this.Height / 4) {
                    dy = -25;
                } else if (e.Y > this.scoperMain.Height * 3 / 4) {
                    dy = 25;
                } else {
                    dy = 0;
                }
            }
        }

        private void Form1_MouseUp(object sender, MouseEventArgs e) {
            dx = 0; dy = 0;
        }

        private void scoper2DRenderer1_MouseMove(object sender, MouseEventArgs e) {
            this.Form1_MouseDown(sender, e);
        }

        private void scoperPreview_Draw(int TickCount) {
            scoperPreview.GraphicsDevice.Clear(Microsoft.Xna.Framework.Graphics.Color.White);
            mapPreview.RenderAll();
        }

    }
}