Undefined array key "id_lista"
#0 /var/www/html/red/usuarios/lista_vaciar.php(6): devel_error_handler()
Array
(
    [errno] => 2
    [message] => Undefined array key "id_lista"
    [file] => /var/www/html/red/usuarios/lista_vaciar.php
    [line] => 6
    [er] => 24565
    [shell] => 
)