Err.HelpContext (property)

Syntax Err.HelpContext [= contextid]
Description Sets or retrieves the help context ID that identifies the help topic for information on the error.
Comments The Err.HelpContext property, together with the Err.HelpFile property, contain sufficient information to display help for the error. When BasicScript generates an error, the Err.HelpContext property is set to 0 and the and the Err.HelpFile property is set to ""; the value of the Err.Number property is sufficient for displaying help in this case. The exception is with errors generated by an OLE automation server; both the Err.HelpFile and Err.HelpContext properties are set by the server to values appropriate for the generated error. When generating your own user-define errors, you should set the Err.HelpContext property and the Err.HelpFile property appropriately for your error. If these are not set, then BasicScript displays its own help at an appropriate place.
Example 

                           'This example defines a replacement for InputBox that deals
                           'specifically with Integer values. If an error occurs, the
                           'function generates a user-defined error that can be trapped
                           'by the caller.
                           Function InputInteger(Prompt,Optional Title,Optional Def)
                           On Error Resume Next
                             Dim x As Integer
                             x = InputBox(Prompt,Title,Def)
                             If Err.Number Then
                               Err.HelpFile = "AZ.HLP"
    Err.HelpContext = 2
    Err.Description = "Integer value expected"
                               InputInteger = Null
                               Err.Raise 3000
                             End If
                            InputInteger = x
                           End Function
                           Sub Main
                             Dim x As Integer
                             Do
                               On Error Resume Next
                               x = InputInteger("Enter a number:")
                               If Err.Number = 3000 Then
                                 Msgbox "Invalid number, press ""F1"" to invoke help" _
                                 ,,,Err.HelpFile,Err.HelpContext
                               End If
                             Loop Until Err.Number <> 3000
                           End Sub
See Also Error Handling (topic), Err.Clear (method), Err.Description (property), Err.HelpFile (property), Err.LastDLLError (property), Err.Number (property), Err.Source (property)