HTML form, Javascript, PHP, and DB connection with MySQL

I have a form and upon filling it out, I want the data to be inserted into a database. As of now, the database has two columns, "feedback" and "date". But right now, only the "date" gets inserted into the database, not the "feedback".

HTML Form:

<form class="form-inline" action="JavaScript:sendFeedback()" method="get">
<textarea name="Feedback" placeholder="Feedback..." rows="5" cols="100"></textarea> 
<button type="submit" class="btn">Tell us</button>
</form>

Javascript:

function sendFeedback() {
    _gaq.push(['_trackPageview', 'OutgoingLink=SendFeedback' ]);
    $.get("../php/NewFeedback.php",{Feedback:$('input[name="Feedback"]').val()});
    var element = document.getElementById("FeedbackArea");
    element.innerHTML = "<div class=\"alert alert-success\"> <a class=\"close\" data-dismiss=\"alert\" href=\"#\">×</a>Thanks for your feedback!</div>";
    return false;
}

php:

$db = MySql::getInstance(DATABASE_HOST, DATABASE_USER, DATABASE_PASS, DATABASE_NAME);
$Feedback = mysql_real_escape_string($_GET['Feedback']);

//create the sql statement
$sql = "INSERT INTO Feedback VALUES('{$Feedback}', CURDATE());";

//execute the query
$res = $db->query($sql);

And like I said, if I type something to the textarea and press the button "Tell us", the Database gets a new entry, but the "Feedback" attribute is empty (and the date is filled in).

Why is this?