$jinput = JFactory::getApplication()->input;
$data = $jinput->get('jform', 'default_value', 'filter');

$data  = $this->input->post->get('jform', array(), 'array');

JHtml::_('jquery.framework'); // make sure jquery is loaded
<script type="text/javascript">
jQuery.post('index.php?option=com_mycomponent&task=component.save',
jQuery( "#yourformid" ).serialize(), function(data,
statustxt){ jQuery('#resultdiv').html=data; })
</script>

print_r($_POST);