1. Remain ur ajax url, just add one more parameter called 'task'
2. After that, in ur ajax, u need create a code to retrieve 'task' parameter from url
$task = JFactory::getApplication()->input->getCmd('task', '');
3. If retrieve the correct parameter, then call the function run
if ($task === 'clearSentValue') {
return $this->clearSentValue();
}
This skill let u able to call specific function from ur ajax