public void Tab(int tab, NoFocusBorderBtn back = null, NoFocusBorderBtn next = null)
        {
            if (tab < this.ColumnCount && tab >= 0)
            {
                foreach (ColumnStyle cs in this.ColumnStyles)
                {
                    cs.Width = 0;
                }
                this.ColumnStyles[tab].Width = 100;

                foreach (Control c in this.Controls)
                {
                    c.Visible = false;
                }
                this.Controls[tab].Visible = true;

                if (back != null && next != null)
                {
                    if (tab == 4)
                    {
                        next.Text = "Install";
                    }
                    else
                    {
                        next.Text = "Next";
                    }
                    next.Enabled = allowed != tab || tab == 4;
                    back.Enabled = tab != 0;
                }

                currentTab = tab;
            }
        }
 public void PrevTab(NoFocusBorderBtn back, NoFocusBorderBtn next)
 {
     Tab(currentTab - 1, back, next);
 }
 public void NextTab(NoFocusBorderBtn back, NoFocusBorderBtn next)
 {
     Tab(currentTab + 1, back, next);
 }