How can I use php to open a file after a certain condition is met?

I want the script to open a file after a certain condition has been met. So far, I have:


%26lt;?php


$file== $_GET['file'];





if ($file%26gt;%26lt;"1"")


echo "Incorrect file!";


else


if ($file=="2")


open file;


?%26gt;





What do I put at the part that says "open file;"?

How can I use php to open a file after a certain condition is met?
Look at the php manual for file functions, it varies according to what you want to do with the file and the type of file.