Stuck in PHP

hi everyone! i have a problem that i am sure someone can clear up for me easily :)

i'm in the middle of creating a website, and want to do it fully in PHP. My aim is to have one ttemplate layout, and call in text files to display the content. i guess the first question should be to check is this actually possible? i'm presuming it is hehe

so, the problem im having is actually getting links to call in the right text file.

the basic set up is a table with two columns. in the left hand column i have a menu.txt file being called up which at the moment just has standard hypertext links. i would like to code it so that as you click on a link, it calls up the relevant text file in to the right hand column of the template.

i've been playing around with the switch command, and it kinda makes sense to me, but i dont know how to specify calling the text file to the right hand column!

can anyone help? advice, code snippets, or i can even email the files im working with so you can see what im wittering on about hehe.

im sure this is going to be something simple that i've just not managed to grasp heh :)
thanks in advance!!
Paul