jquery - Pass value from ajax variable to a php variable -

when use ajax value in server side, on successful execution can shown using

.done(function(data) {console.log(data)} 

the result of ajax inside "data". question can pass value of "data" in php variable.

my scenario : there dropdown, below html table. when user selects item in dropdown, using ajax selected values passes in "data".

after running mysql query

"select name, age, sex student name = '{$retvalue}';

now instead of "??", want pass value inside "data" in php variable $retvalue.

how can achieve this?

i have tried level best , after thorough search in net, not able find anything.

code follows : main - file

<?php      include ("dbcon.php");      include ("included_functions.php"); ?>  <section>    <script type="text/javascript" src="<?php bloginfo('template_url');?>/js/jquery.min.js"></script>    <script src="<?php bloginfo('template_url');?>/js/jquery-1.9.1.js"></script>    <script type="text/javascript">      $(document).ready(function(){     $("#fyearddl").change(function(){       /* drop down list */       var fyear = $(this).val();       data = {fyear:fyear};       $.ajax({         type: "get",         url: '<?php bloginfo("template_url");?>/showonselectfy.php',          data: data,         cache: false       })       .done(function(data) {         console.log(data);               $('#inboxfy').empty();         $('#inboxfy').val(fyear);       })     });      });     </script>     <div style="width:100%; height:30px; padding-bottom:45pt; background-color:#fff"></div>       <form id="formcatg" action="" method="post">     <div class="centr-div">       <div class="divbox">         <label id="ddltxt">to view&nbsp;:&nbsp;</label>         <?php           $fyquery = "select fyear finyear";           $fyresult = mysqli_query($connection, $fyquery);           echo "<select id='fyearddl' name='fyearddl'>";           echo "<option value = '-- select financial year --'>-- select financial year --</option>";             while ($resultarr = mysqli_fetch_assoc($fyresult)){               echo "<option value  = '$resultarr[fyear]'>$resultarr[fyear]</option>";             }            echo "</select>";         ?>         <input id="inboxfy" type="text" name="inboxfy" value="" style="width:20%; height:15pt" />        </div>        <div id="tablediv" class="scroll">          <table id="showselfy">            <thead>              <tr>               <th>s.no.</th>                   <th>quantity</th>               <th>price&nbsp;(&nbsp;&pound;&nbsp;)&nbsp;</th>              </tr>            </thead>             <?php             //$query="select rt_id, rt_qty, rt_cost,fin_yr rate_mast fin_yr='2014-2015'";             $ddlvalue = $_post['fyearddl'];            $query="select rt_id, rt_qty, rt_cost rate_mast fin_yr='{$ddlvalue}'";             $retval = mysqli_query($connection, $query);            while( $retvalarr = mysqli_fetch_assoc($retval)){         ?>         <tbody>            <tr>              <td><?php echo $retvalarr['rt_id'] ?></td>              <td><?php echo $retvalarr['rt_qty'] ?></td>              <td><?php echo $retvalarr['rt_cost'] ?></td>              <td style="display:none"><?php echo $retvalarr['fin_yr'] ?></td>            </tr>         </tbody>         <?php } ?>           </table>         </div>         <span id="dataresult"></span>       </div>     </div>       </div>     </form> </section>           <?php     mysqli_close($connection); ?> <?php //get_footer(); ?> 

showonselectfy.php

<?php var_dump($_get); ?> <?php   include("dbcon.php");   include("included_functions.php");    if(isset($_get['fyear'])){     $getfinyear = $_get['fyear'];     echo $getfinyear;   } ?>  <?php    mysqli_close($connection); ?>