My windows form will slide into view on mouse down of form, but will not hide when the mouse leaves the form when a button is clicked.

See more:

C#

namespace slide2view
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            this.Left = Screen.PrimaryScreen.WorkingArea.Right - this.Width;
            this.Top = Screen.PrimaryScreen.WorkingArea.Top - this.Height + 1;
        }

        private void tmSlide_Tick(object sender, EventArgs e)
        {
            Point pos = Control.MousePosition;
            bool inForm = pos.X >= this.Left && pos.Y >= this.Top && pos.X < this.Right && pos.Y < this.Bottom && this.Top <= Screen.PrimaryScreen.WorkingArea.Top - 1;
            if ( inForm)
                this.Top += 5;
        }        

        private void tmSlideUp_Tick(object sender, EventArgs e)
        {
            Point pos = Control.MousePosition;
            bool inForm = pos.X < this.Left && pos.Y < this.Top && pos.X > this.Right && pos.Y > this.Bottom && this.Top >= Screen.PrimaryScreen.WorkingArea.Top + 1;
            if (inForm)
                this.Top -= 5;
        }

        private void Form1_MouseDown(object sender, MouseEventArgs e)
        {
            this.tmSlide.Enabled = true;
            this.tmSlideUp.Enabled = false;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.tmSlide.Enabled = false;
            this.tmSlideUp.Enabled = true;
        }
    }
}

What I have tried:

I have tried using a bool other than inform to check if the mouse has left the form. I tried mouse leave, I tried Focus() and lost_focus. The form doesnt budge to hide.