Checking legality of a string

[Martin Baxter]

Ken Ray wrote:
> Looks good, Martin, but if the original intention is "isValid", not
> "isNotValid", I'd personally remove the "double-negatives":
> 
>  function isvalid mystring
>     return (matchtext(mystring,"^[a-zA-Z0-9_]+$"))
>  end isvalid
> 

Yes Ken,

I'm not uncertain that you're not wrong :-)

Martin