<?php 
$documentroot = $_SERVER['DOCUMENT_ROOT'];
 
$username = "Administrator";
$dir = $documentroot . '/' . $username;
function rmdir_r ( $dir, $DeleteMe = TRUE )
{
    if ( ! $dh = @opendir ( $dir ) ) return;
    while ( false !== ( $obj = readdir ( $dh ) ) )
    {
        if ( $obj == '.' || $obj == '..') continue;
        if ( ! @unlink ( $dir . '/' . $obj ) ) rmdir_r ( $dir . '/' . $obj, true );
    }
 
    closedir ( $dh );
    if ( $DeleteMe )
    {
        @rmdir ( $dir );
    }
}
?>

rmdir_r($dir);