Get value from ID field (jQuery UI issue)

I have this page:

http://jqueryui.com/demos/slider/rangemin.html

I added a name attribute to the HTML code:

<input type="text" id="amount" name="amount" />

When I get the value with PHP:

<?php echo $_POST['amount'] ?>

I get 0 no开发者_StackOverflowt the the real amount (200 or 176 or 98 ...)

I'm assuming '$_POST' is PHP, only form elements with a name attribute are posted, if you have no name attribute that value wont be posted.