private void pic(bool bl)
 {
     if (pictureBox1.InvokeRequired)
     {
         picbool b = new picbool(pic);
         this.Invoke(b, new object[] { bl });
     }
     else
     {
         pictureBox1.Visible = bl;
     }
 }
        private void pic(bool bl)
        {
            if (pictureBox1.InvokeRequired)
            {
                picbool b = new picbool(pic);
                this.Invoke(b, new object[] { bl });

            }
            else
            {
                pictureBox1.Visible = bl;
            }
        }