Marc,

I have authentication table in server containing columns

UserOrRoleName - John, Seller, Manager, Marc etc.
Privilege - Invoice, Order etc.
Access level -  Read, Write, Post etc.
Department  - Sales, Support  etc.

I assume that you are referencing a code below.
I have no idea how using any .NET classes with this table to create
AccessLevel( UserOrRoleName, Privilege Department  ) function.
So it seems that I must implement my custom authentication.

Andrus.

For info, here is a rough sketch of what the component would look
like... this allows both IDE and programmatic usage; note that for
roles-based security you'd also need to initialize the principal - at
the most primative this can be as simple as:

           Thread.CurrentPrincipal = new GenericPrincipal(
               new GenericIdentity("Marc"), // name of user
               new string[] { "BASIC" } // array of roles that the
user has
           );

Obviously if your security model is more complex, you may need to
change things ;-p

   [ProvideProperty("Role", typeof(Control))]
   [ToolboxItemFilter("System.Windows.Forms")]
   [Description("Provides automatic role-checking")]
   public class RoleDisabler : Component, IExtenderProvider
   {
       private Dictionary<Control, string> map
           = new Dictionary<Control, string>();
       [DefaultValue("")]
       public string GetRole(Control control)
       {
           if (control == null) return "";
           string role;
           map.TryGetValue(control, out role);
           return role ?? "";
       }
       public void SetRole(Control control, string role)
       {
           if (control == null) return;
           bool add = false, remove = false;
           if (string.IsNullOrEmpty(role))
           {
               remove = map.Remove(control);
           }
           else
           {
               add = !map.ContainsKey(control);
               map[control] = role;
           }
           if (!DesignMode)
           {
               SetEnabled(control);
               if (add)
               {
                   control.ParentChanged += control_ParentChanged;

               }
               else if (remove)
               {
                   control.ParentChanged -= control_ParentChanged;
               }
           }
       }
       private void SetEnabled(Control control)
       {
           if (DesignMode || control == null) return;
           string role;
           if (map.TryGetValue(control, out role))
           {
               IPrincipal principal = Thread.CurrentPrincipal;
               control.Enabled = principal == null ? false :
principal.IsInRole(role);
           }
       }
       void control_ParentChanged(object sender, EventArgs e)
       {
           SetEnabled(sender as Control);
       }
       bool IExtenderProvider.CanExtend(object obj)
       {
           return obj is Control;
       }
   }