private void Form1_MouseClick(object sender, MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Right)
{
Control cntrl = (Control)(sender);
int x = cntrl.Left + e.X + (cntrl.Width - cntrl.ClientRectangle.Width)/2;
int y = cntrl.Top + e.Y - (cntrl.Height - cntrl.ClientRectangle.Height)/2;
Point pointer_location = new Point(x, y);
this.njb_menu_manager.showMenu(pointer_location, "File");
}
}