How to add and use jquery and css file in joomla module..?

$document = &JFactory::getDocument();//getting document ref object
$document->addScript(JURI::root() . 'modules/mod_my_slider/jquery.js');

$path = "http://".$_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF']."modules/mod_my_slider/images";
$path = str_replace("index.php","",$path);
?>
<scr开发者_JAVA百科ipt language="javascript">
  jQuery('#block').show();
 </script>
 <center>
 <div height:220px; width:500px; border:1px solid black;>
  <img class="slide" height="220px" width="500px" src="<?php echo $path; ?>/pier1.jpg"/>
 </div>
 <div id="block" style="height:100px; width:10px; display:none; background-color:white;">BETA</div>
 </center>
?>

I try like above,i also include file of jquery but that line not display.

---

$document =& JFactory::getDocument();
$document->addScript($url);
$document->addStyleSheet($url);

This is definitely the correct syntax for adding jscript and CSS to a module. The only issue I can see is that Joomla automatically puts JS files in modules/module_name/js and CSS in modules/module_name/css folders if you use the installer. If the line is not there at all then you have another issue, if the line is there but the file is not added, you probably need to change your code to

$document->addScript(JURI::root() . 'modules/mod_my_slider/js/jquery.js');