HTML - Change\Update page contents without refreshing\reloading the page

I get the data from DB and display it in a div... what I want to do is when I click a link it should change the content of the div

one option is to pass parameter through URL to itself and reload the page...

I need to do it without reloading\refreshing...

<?php   
    $id   = '1';

    function recp( $rId ) {
        $id   = $rId;
    }
?>

<a href="#" onClick="<?ph开发者_StackOverflowp recp('1') ?>" > One   </a>
<a href="#" onClick="<?php recp('2') ?>" > Two   </a>
<a href="#" onClick="<?php recp('3') ?>" > Three </a>

<div id='myStyle'>
<?php
    require ('myConnect.php');     
    $results = mysql_query("SELECT para FROM content WHERE  para_ID='$id'");

    if( mysql_num_rows($results) > 0 ) {
        $row = mysql_fetch_array( $results );
        echo $row['para'];
    }
?>
</div>

The goal is when I click any of the links the contents of the div and php variable\s gets updated without refreshing.... so that user could see new data and after that if some query is performed it is on new variable\s

p.s I know it is gonna require some AJAX but I don't know AJAX.. so please reply with something by which I can learn... my knowledge is limited to HTML, PHP, some JavaScript & some jQuery

You've got the right idea, so here's how to go ahead: the onclick handlers run on the client side, in the browser, so you cannot call a PHP function directly. Instead, you need to add a JavaScript function that (as you mentioned) uses AJAX to call a PHP script and retrieve the data. Using jQuery, you can do something like this:

<script type="text/javascript">
function recp(id) {
  $('#myStyle').load('data.php?id=' + id);
}
</script>

<a href="#" onClick="recp('1')" > One   </a>
<a href="#" onClick="recp('2')" > Two   </a>
<a href="#" onClick="recp('3')" > Three </a>

<div id='myStyle'>
</div>

Then you put your PHP code into a separate file: (I've called it data.php in the above example)

<?php
  require ('myConnect.php');     
  $id = $_GET['id'];
  $results = mysql_query("SELECT para FROM content WHERE  para_ID='$id'");   
  if( mysql_num_rows($results) > 0 )
  {
   $row = mysql_fetch_array( $results );
   echo $row['para'];
  }
?>

jQuery will do the job. You can use either jQuery.ajax function, which is general one for performing ajax calls, or its wrappers: jQuery.get, jQuery.post for getting/posting data. Its very easy to use, for example, check out this tutorial, which shows how to use jQuery with PHP.