Why setting superglobal variable $GLOBALS['foo'] doesn't work?
===

The following code produces a warning:

    <?php
    $GLOBALS['foo'] = "Example content<BR><BR>";
    echo $foo; // that works!
    Test();
    
    function Test()
    {
        echo $foo; // that doesn't work!
    }
    ?>
The warning is:

`Notice: Undefined variable: foo`

How come ?