//Performs fade increment.

private void timer_Tick(object sender, EventArgs e)
{
    double fadeChangePerTick = timer.Interval * 1.0 / 1000 / fadeTime;

    //Check to see if it is time to stop the timer

    if (Math.Abs(targetOpacity - this.Opacity) < fadeChangePerTick)
    {
        //There is an ugly black flash if you set the Opacity to 1.0

        if (targetOpacity == 1) this.Opacity = .999;
        else this.Opacity = targetOpacity;
        
        //Process held Windows Message.

        base.WndProc(ref heldMessage);
        heldMessage = new Message();
        
        //Stop the timer to save processor.

        timer.Stop();
    }
    else if (targetOpacity > this.Opacity) this.Opacity += fadeChangePerTick;
    else if (targetOpacity < this.Opacity) this.Opacity -= fadeChangePerTick;
}