structure/enum question

[alex_read]

I've got a program installed here which has a form which people can fill out. One of it's drop down boxes allows you to select a value from either "default", "none" or you can enter a value from 0 to 100 in it (for a percentage).

I want to expose ths field from a class I'm writing, so when a class instance is created, this value can be set & a method called to fill this entry in the form.

What is the best / most professional way of exposing something like this which can allow multiple data types? I don't really want to expose this as a string if I can help it to minimize the chance of a wrong figure being specified.

Public Structure xyz
    Public _default as boolean
    Public none     as Boolean 
    Public Percentage as system.web.ui.webcontrols.unit
End Structure
 
Public Enum xyz
    _default     = 0
    none         = 1
    _1percent    = 2
    _2percent    = 3
    ...
    _100percent  = 102
End Class

These are about the only ways I can think of, neither of which look any good! Can anyone recommend how I could do this please?

Thanks!