Using $this when not in object context

You can get error messages like this: Using $this when not in object context in foo.php on line 6

if you use $this outside of a class.

Note that you were allowed to use $this outside of classes in PHP4, but PHP5 does not allow it.

WRONG $this->foo=7; // not legal outside of a class

RIGHT class Foo {   function foo {      $this->foo=7;  // legal inside a class } }