http - Passing a value with ajax and catching with php -

after 3 days , many lame questions on community,i finnaly understand little bit of ajax post...still couldnt find answer 1 little problem.how catch value passed ajax,with php?

$(document).on('click','tr.listcontractrow', function(e){     var path = $(this).data('path');      $.post("contract.php", {id: path}, function(data){         alert("data sent , received: " + path);     }); }); 

the values sent, i've tested it,the alert shows right value,i checked console log.but somehow cant catch php....:

if(isset($_post['id'])){     $var = $_post['id']     echo $var; } 

but without succes.any ideas? update:

echo '<table>'; $row=mysql_fetch_array($query){ echo '<tr class="listcontractrow" data-path="'.$row['id'].'">'; echo '<td></td>'; echo '<tr>'; } echo '</table>'; 

the visible thing can see there missing semicolon in php:

if(isset($_post['id'])){    $var = $_post['id'];    echo $var; } 

i replicated code , working in dev environment.