What am I doing wrong

Hello and thank you for script, just what I need for a school project.

I started by using your example script and cannot get to work? What is the correct way to make your example work?

This is what I get:

Warning: fopen(exampleScript.php) [function.fopen]: failed to open stream: No such file or directory in I:\local\htdocs\crypto\CriptoPHP.php on line 23

Warning: filesize() [function.filesize]: stat failed for exampleScript.php in I:\local\htdocs\crypto\CriptoPHP.php on line 24

Warning: fread() expects parameter 1 to be resource, boolean given in I:\local\htdocs\crypto\CriptoPHP.php on line 24

Warning: fclose() expects parameter 1 to be resource, boolean given in I:\local\htdocs\crypto\CriptoPHP.php on line 25

Parse error: syntax error, unexpected $end in I:\local\htdocs\crypto\CriptoPHP.php(34) : eval()'d code on line 1

Many thanks for your help.