Picbox del

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 WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        bool sel = false;

        public Form1()
        {
            InitializeComponent();
        }

        private void pictureBox1_Click(object sender, EventArgs e)
        {
            if (sel == true)
            {
                pictureBox1.BorderStyle = BorderStyle.None;
                sel = false;
            }
            else
            {
                pictureBox1.BorderStyle = BorderStyle.FixedSingle;
                sel = true;
            }
        }

        private void Form1_KeyDown(object sender, KeyEventArgs e)
        {
            if (sel)
            {
                pictureBox1.Visible = false;
            }
        }
    }
}