I am using Joomla 2.5.11 . I have a php file stored in the /public_html/joomtest/components/com_jumi/files which is pasted below. I have a PHP form which is stored in the same location i.e /public_html/joomtest/components/com_jumi/files.
I want the PHP form to call the PHP script so that an article is created in Joomla. But whenever the PHP script is called, I receive the below error
Fatal error: Class 'JTable' not found
and the line on which Joomla throws error is
$table = JTable::getInstance('Content', 'JTable', array());
PHP script
<?php
$table = JTable::getInstance('Content', 'JTable', array());
$data = array(
    'catid' => 8,
    'title' => 'SOME TITLE',
    'introtext' => 'SOME TEXT',
    'fulltext' => 'SOME TEXT',
    'state' => 0,
);
if (!$table->bind($data))
{
    $this->setError($table->getError());
    return false;
}
if (!$table->check())
{
    $this->setError($table->getError());
    return false;
}
if (!$table->store())
{
    $this->setError($table->getError());
    return false;
}
?>
</body>
</html>
I tried putting in
require_once('/libraries/joomla/database/table.php');
but this again didnt work. Please help.