visibility of menu items

public static void function_name(int a2)
{
    try
    {
        string sql_string_sfunction_name = ("Data Source=32423424;Initial Catalog=sdgsdgasdg;User Id=gdggdfg;Password=sdertet;");
        SqlConnection conn1 = new SqlConnection(sql_string_sfunction_name);
        SqlCommand command1 = new SqlCommand("proc_function_name2", conn1);
        conn1.Open();
        command1.CommandType = CommandType.StoredProcedure;
        command1.Parameters.AddWithValue("@fnid", a2);
        SqlDataReader rdr1 = command1.ExecuteReader();
        if (rdr1.HasRows)
        {
            StringBuilder sb1 = new StringBuilder();
            while (rdr1.Read())
            {
                sb1.Append(((string)rdr1["systemfname_vc"]).ToString());
                function_name_string = sb1.ToString();
                function_list_display.Add(function_name_string);
                SecurityModule sm = new SecurityModule();
                sm.formm_display_function(function_name_string);
            }
        }
        else
        {
            MessageBox.Show("not found");
        }
        rdr1.Close();
        command1.ExecuteNonQuery();
        conn1.Dispose();
        conn1.Close();
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
        MessageBox.Show("Error in database connection");
    }
}

public void formm_display_function(string display_form_str)
{
    foreach (ToolStripMenuItem menuItem in menuStrip1.Items)
    {
        foreach (ToolStripMenuItem subitem in menuItem.DropDownItems)
        {
            if (subitem.Name.Trim() == display_form_str)
            {
                subitem.Visible = true;
                break;
            }
        }
    }
}