fun other () = redirect (bless "http://www.google.com/")
fun further () = case checkUrl "http://www.google.com/" of
None => return Darn.
| Some url => redirect url
fun failing () = case checkUrl "http://www.yahoo.com/" of
None => return Darn.
| Some url => redirect url
fun main () = return
Go there
Go also there
Fail there