protected void Data_g_ItemDataBound(object sender, DataGridItemEventArgs e)
{
  if (e.Item.ItemType == ListItemType.AlternatingItem || e.Item.ItemType == ListItemType.Item)
  {
    String A = DataBinder.Eval(e.Item.DataItem, "A").ToString();
    String B = DataBinder.Eval(e.Item.DataItem, "B").ToString();
    String C = DataBinder.Eval(e.Item.DataItem, "C").ToString();
    TextBox TextBox1 = e.Item.FindControl("TextBox1") as TextBox;
    if (A == "1") TextBox1.ReadOnly = true;
    ImageButton B1 = e.Item.FindControl("B1") as ImageButton;
    ImageButton B2 = e.Item.FindControl("B2") as ImageButton; 
    ImageButton B3 = e.Item.FindControl("B3") as ImageButton;
    ImageButton B4 = e.Item.FindControl("B4") as ImageButton;
    if (C == "1")
    {
      B3.Visible = false;
      B4.Visible = false;
    }
    else if (C == "2")
    {
      B1.Visible = false;
      B2.Visible = false;
    }      
  }
}