<?php

session_start();
if (!isset($_SESSION['username'])) {
    ?>
<script language="JavaScript">window.open("../../index.php", "_self")</script><?php 
}
require_once "../../modelo/columnas_extra.class.php";
$id_columna = $_POST["id_columna"];
$Columnas = new Columnas();
$delColumnas = $Columnas->del_columnaById($id_columna);
if ($delColumnas) {
    echo "ok";
} else {
    echo "error";
}