testThis.class.php: This class allows you to test constraints using one line of code.

This class allows you to test constraints using one line of code.
This is usefull if you are checking for required conditions at the top of a
page. It hase 2 action levels for a return of false -- 1 displays an
error message (customizable) and kills the execution of the script. 2 returns
a false and displays the error message. There is also an example on how to
create additional methods. For this I chose to implement the file include
directives require() and include().