Im trying to get some data to show in a placeholder

Im trying to get some data to show in a place holder from a database. I have a php file that gets the data from the database and echo's it as a json_encode, In animate I have a place holder in which to print the data, I cant get the data to print in the placeholder. the code on the php is as follows

********************************************************************** ********************************************************************** *

$result = mysql_query("SELECT id, name, email, message FROM feedback") or die(mysql_error());

$json = array();

//// Puts it into an array

while($r = mysql_fetch_array( $result )) {

    $json[] = $r;

}

echo json_encode($json);

********************************************************************** ********************************************************************** *

the code in creation complete is as follows

********************************************************************** ********************************************************************** *

$.ajax({

url: 'retrievefeedback.php',

dataType: 'json',

success: function(data) {

    sym.$("placeholder").html(data);

     }

     });

********************************************************************** ********************************************************************** *

Any help would be appreciated