public abstract class AsynchronousEventHandlerBase : ICSAsyncEventHandler, 
	IDisposable

Public MustInherit Class AsynchronousEventHandlerBase
	Implements ICSAsyncEventHandler, IDisposable

public class MyOnDocumentSaveAsyncHandler : AsynchronousEventHandlerBase
{
    string status;
    protected override void DoWork()
    {
        //Check the permission, only members in a specific domain can execute the 
        //operation.
        if (!CallerLogOnName.StartsWith(@"MyDomain\", StringComparison.OrdinalIgnoreCase))
        {
            //Create a message that indicates that the operation was a failure
            //but the event handler itself did not fail.
            status = String.Format("Operation was not performed, Permission denied for user '{0}'.", CallerLogOnName);
            return;
        }

        //Do some work here.
        // 
        // 

        //create a success message to return to Content Studio
        status = String.Format("The operation has been performed by '{0}'.", CallerLogOnName);
    }

    protected override string Finish()
    {
        //Tell Content Studio about the outcome of the operation
        Status = status;
    }

    protected override bool ValidateEvent(int csEvent)
    {
        //Make sure that only OnDocumentSave (csEvent is 11)
        //can be handled by this event handler.
        return csEvent == 11;
    }
}

Public Class MyOnDocumentSaveAsyncHandler 
             Inherits AsynchronousEventHandlerBase
    Dim theStatus As String
    Protected Overrides Sub DoWork()
        'Check the permission, only members in a specific  
        'domain can execute the operation.
        If (Not CallerLogOnName.StartsWith("MyDomain\", StringComparison.OrdinalIgnoreCase))
            'Create a message that indicates that the operation was a failure
            'but the event handler itself did not fail.
            theStatus = String.Format("Operation was not performed, Permission denied for user '{0}'.", CallerLogOnName)
            Return
        End If

        'Do some work here.
        '
        '

        'create a success message to return to Content Studio
        theStatus = String.Format("The operation has been performed by '{0}'.", CallerLogOnName)
    End Sub

    Protected Overrides Sub Finish()
        'Tell Content Studio about the outcome of the operation
        Status = theStatus
    End Sub

    Protected Overrides Function ValidateEvent(csEvent As Integer) As Boolean
        'Make sure that only OnDocumentSave (csEvent is 11)
        'can be handled by this event handler.
        If csEvent = 11 
           Return True
        Else
           Return False
        End If
    End Function
End Class