Property:  Err.HelpContext
Implemented in version 1.0
 
object.HelpContext [ = contextID]

This property is used to set or return a context ID for a Help topic specified with the HelpFile property. If no specific Help file is defined in your code then one of two things can happen. Firstly, VBScript checks to see if the Number value of the Err object relates to a known runtime error. If it does then the VBScript Help context ID for that error is used. However, if the Number property value is not recognised, then VBScript will display the Help contents screen.

Code:
<%
On Error Resume Next
Err.Raise 10
Err.HelpFile = "userhelp.hlp"
Err.HelpContext = usercontextID
If Err.Number <> 0 Then
   MsgBox "Press F1 for help", , "Error: " & Err.Description, Err.Helpfile, _
                 Err.HelpContext
End If
%>