Cached PERL programs

I wrote a bunch of programs to be used as a shopping cart for a customer of mine. It seems to work fine most of the time, but there is apparently a small problem. When a customer adds an item to their shopping a program adds writes the necessary data to a file and then refers the browser to a program that displays the current contents of the shopping cart. The problem is that some customers are getting a cached version of their cart and have to click refresh to see the updated version after they add an item. I have never experienced this problem directly and know nothing of the browser version or settings of the people having this problem.

Is there any way to force a browser to display the current version of a page?

Have your script send a

<META HTTP-EQUIV="Pragma" CONTENT="no-cache">

In the head section of your HTML, or send the equivelant HTTP header if you prefer to do it that way.

That is exactly what I discovered in my web search, but thank you for taking the time to reply.