mysql_real_escape_string() expects parameter 1 to be string

[system]

Warning: mysql_real_escape_string() expects parameter 1 to be string, array given in /home/skymcom/public_html/forum/file.php on line 4

i got this error, i included this file in a file & file.php containg
[php]<?php
$_GET = array_map(‘mysql_real_escape_string’, $_GET);
$_POST = array_map(‘mysql_real_escape_string’, $_POST);
$_COOKIE = array_map(‘mysql_real_escape_string’, $_COOKIE);
$_SERVER[‘HTTP_USER_AGENT’] = mysql_real_escape_string($_SERVER[‘HTTP_USER_AGENT’]);
?>[/php]

[plintu]

[php]
function escape_it($value) {
if (is_array($value))
array_map(‘escape_it’, $value);
else
$value = mysql_real_escape_string($value);
}

$_GET = escape_it($_GET);
$_POST = escape_it( $_POST);
$_COOKIE = escape_it($_COOKIE);
$_SERVER[‘HTTP_USER_AGENT’] = mysql_real_escape_string($_SERVER[‘HTTP_USER_AGENT’]);
[/php]