New table making reference to existing

I had a database like folow:

CREATE TABLE `questions` (
`id` int(11) NOT NULL auto_increment,
`tipo` tinyint(4) NOT NULL default '2',
`enunciado` text NOT NULL,
`created` timestamp NOT NULL default CURRENT_TIMESTAMP,
`updated` timestamp NULL default NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB;

CREATE TABLE `questions_itens` (
`id` int(11) NOT NULL auto_increment,
`questions_id` int(11) NOT NULL,
`txtoption` text NOT NULL,
PRIMARY KEY (`id`),
KEY `questions_id` (`questions_id`),
CONSTRAINT `questions_itens_ibfk_1` FOREIGN KEY (`questions_id`)
REFERENCES `questions` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB

and now, i need to make a new table "tests" that it makes reference to
table "questions".
When a row of table "tests" to make reference to table "questions",
the questions table do not execute "delete".
how I can make this?

sorry my english