Nedd help using Inno Setup

I'm creating a setup using Inno Setup.

I need to define a set of variables to manage ftp connection.

Code:

---

[Setup]
AppName=My Program
AppVerName=My Program version 1.5
DefaultDirName={pf}\My Program
DefaultGroupName=My Program
FtpUSER=
FtpPassword=
FtpHost=

---

The user can value this variables and this values need to start ftp.

How can I do it?

Thank you