在php上删除文档

Question

I want to delete a document with PHP. My database is Mongodb.

This is my database article : The collection is articles

{ "_id" : ObjectId("55be575271dd7ec905b7acda"), "title" : "test", "content" : "Test", "user" : "Paul", "saved_at" : ISODate("2015-08-02T17:49:45.776Z"),  }
> 

So for example if I want to delete an article. I have tried this code :

ListArticle.php :

try {
           $connection = new MongoClient();
           $database   = $connection->selectDB('blog');
           $collection = $database->selectCollection('articles');
         } catch(MongoConnectionException $e) {
           die("Failed to connect to database ".$e->getMessage());
}
            $query=array();
            $cursor=$collection->find($query);
            foreach ($cursor as $doc) {
                echo " Title : ".$doc['title']." "."by ".$doc['user'];                  
                ?>
                <form method="POST" action="script.php" onsubmit="return confirm('do you want to delete this article ?')">
                <br/>
                <?php 
                echo "<input type='submit' value='Delete'>";
                $v=$doc["content"];
                echo "<input type='hidden' name='content' value=$v>";
                echo "</form><br/>";
}

script.php :

try
            {
            $connection = new MongoClient();
            $database = $connection->selectDB('blog');
            }

        Catch(MongoException $e)
            {
            die("Failed to connect to database " . $e->getMessage());
            }

  $collection = $database->articles;



    $query=array("content"=>$_POST["content"]);
    $collection->remove($query);

    echo "<p>Success !</p>";


    ?>

When I click delete article it does not remove

Thanks with the help