I don't think you can do this:
//test.php
function test(){
echo "Hello World";
}
//test.class.php
class test{
require("test.php");
}
//new.php
$new = new Test;
$new->test();
I am not sure about this, but why don't you just put it in one object class?
class test{
function ThisTest(){
echo "Hello World";
}
}