MySQL delete row with AJAX and JSON failed - php

Question

I try to DELETE a row in mysql. I got help to insert and it works well. I tried to use the same logic for delete one row with ID identification, but I can not delete the row.
What is wrong in this code?
...
Here is the full code:
Javascript:
function jsRecordDeleteWrite()
{
var jsObject = {
"ID": document.form_articles.ID.value
};
// ... the AJAX request is successful
var updatePage = function (response) {
alert("record successful deleted");
};
// ... the AJAX request fail
var printError = function (req, status, err) {
alert("deletingt record failed");
};
// Create an object to describe the AJAX request
$.ajax({
url : 'deletearticle.php',
dataType : 'json',
contentType: 'application/x-www-form-urlencoded',
data : jsObject,
type : 'POST',
success: updatePage,
error: printError
});
}
Here is deletearticle.php
<?php
$link = mysql_connect('localhost', 'admin0', 'star1star1star0');
if (!$link) {
die('Could not connect: ' . mysql_error());
}
$db_selected = mysql_select_db('sob', $link);
if (!$db_selected) {
die ('Can\'t use foo : ' . mysql_error());
}
//read the json file contents
$ID = $_POST['ID'];
//delete item from mysql table
$sql = mysql_query("DELETE FROM articles WHERE ID=$ID");
if(!mysql_query($sql))
{
die('Error : ' . mysql_error());
}
//database connection close
mysql_close($link);
//}
?>

Answer 1

Verify that the server receives in php
var_dump($ID);
If query is right, check the mysql user has rights to update table

Answer 2

Put single quotes around $ID:
//delete item from mysql table
$sql = mysql_query("DELETE FROM articles WHERE ID= '$ID'");