dynamic MySQL table using php but javascript function only calling first row not others? [duplicate]

This is php mysql code:

<?php $user_apply_data=mysql_query("SELECT * FROM apply");
 while ($user_apply_field = mysql_fetch_assoc($user_apply_data)) {  ?>
<tr>
<td><button class="btn btn-xs btn-success" id="apply" data-send="<?php echo $user_job_field['job_category']; ?>">Apply</button>
</td>
</tr>
 <?php } ?>

This is script:

$("#apply").click(function() {
            var check = $(this).data("send");
    alert(check);
            });

Output : first-row calling function rest are not