I have an html page that starts a series of calls to CGI routines which build and return more HTML documents calling other CGI routines. I can't figure out a simple way to check that the data is passed correctly between these.
There is 2 type of data passed, one in
<input type .."hidden"..> and another in a
<input type .."radio"..> list and then the returned selection.

Perhaps someone with this kind of experience can give a few tips or advices on how to proceed.

Thank you very much for your help.

In the form tag, set the method to "get". Then the value of the tags will be in the resulting URL.

Well, a solid design is a starting point

You could write a function called 'ValidateInput' which gets called first. I tend to program using objects now, so I would probably have a constructor that does similiar tasks.

Web programming can get ugly if you don't take careful time to walk through an application, because theres a few ways data can be passed between pages (sessions,cookies,GET data,POST data). I like drawing flowcharts and what are probably known as 'use cases' even though I've never formally read about them. Its important for me to visualize what data is being passed to what pages so I know what data I'm working with in each page/script/whatever.

Thank you both.
To ChasH.in.NC, this is a very good idea, and simple too.
To lowpro2k3: my problem with a function is how to have the function warn me since the screen is not available, I've tried this and didn't get the message I wanted to display.