function addCategory()
{
$controllerCategory = new ControllerCategory();
$category = new Category();
$category->category = htmlspecialchars(trim(strip_tags($_POST['category'])));
$category->category_icon = '';
$category->created_at = time();
$category->updated_at = time();
$controllerCategory->insertCategory($category);
echo "<script type='text/javascript'>location.href='categories.php';</script>";
}