Upgrade from Delphi 3 to Delphi 5 Professional


We are considering to upgrade our applications, written in Delphi 3 -
Client/Server Suite, to Delphi 5 - Professional. In our application we use
most of the internet components.

If we recompile our existing applications with D5 - Professional, will this
go smoothly, or
will it need a lot of rewriting?

Please advise,

Many thanks