Implementing a dynamic form with PHP,MySQL and AJAX

Hi,
I am trying to implement a dynamic form where in I can add the form elements basically two select boxes and a textarea. The select box is a chained one which is populated from a mysql database. The first row of my form is predefined and is working properly as expected. The first select data is sent to a php file for processing through AJAX and the list is retrieved.
But when i create the form elements dynamically, I am not able to perform this operation. Here is my code,

The form page

Code:

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  <tbody>
                  <tr> 
                      <td><input type="checkbox" required="required" name="chk[]" /></td>         
                                                <td>
                            <label for="drop_1">Product Type</label>
                                <select name="drop_1[]" id="drop_1">
                                    <option value="" selected="selected" disabled="disabled">Select a Category</option>
                                    <?php getTierOne();?>
                                </select>
                            </td>
                          <td> 
                            <span id="wait_1" style="display: none;">
                                <img alt="Please Wait" src="images/ajax-loader.gif"/>
                            </span>
                              </td>
                                <?php
                                        echo "<input type='hidden' name='userid' value=$user_id />";
                                ?>
                                <td><span id="result_1" style="display: none;"></span></td>
                                        <td><label for="comment">Comments</label><textarea id="comment" name="comment" rows="5" cols="8"></textarea></td>
                    </tr>
                   
                    </tbody>

---

AJAX

Code:

---

$(document).ready(function() {
        $('#wait_1').hide();
        $('#drop_1').change(function(){
          $('#wait_1').show();
          $('#result_1').hide();
      $.get("dynamic.php", {
                func: "drop_1",
                drop_var: $('#drop_1').val()
      }, function(response){
        $('#result_1').fadeOut();
        setTimeout("finishAjax('result_1', '"+escape(response)+"')", 400);
      });
            return false;
        });
});

function finishAjax(id, response) {
  $('#wait_1').hide();
  $('#'+id).html(unescape(response));
  $('#'+id).fadeIn();
}

---

Dynamic field creation

Code:

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var i = $('#dataTable tr').size() + 1;
        $(function () {
            var scntDiv = $('#dataTable');

            $("#addScnt").click(function (e) {
                $('<tr><td><input type="checkbox" required="required" name="chk[]" /></td><td><label for="drop_1_' + i + '">Product Type</label><select name="drop_1[]" id="drop_1_' + i + '"><option value="" selected="selected" disabled="disabled">Select a Category</option><option value="abcd">abcd</option><option value="efgh">efgh</option></select></td><td><span id="wait_1_' + i + '" style="display: none;"> <img alt="Please Wait" src="images/ajax-loader.gif"/></span></td><td><span id="result_1_' + i + '" style="display: none;"></span></td><td><label for="comment_' + i + '">Comments</label><textarea id="comment_' + i + '" name="comment[]" rows="5" cols="8"></textarea></td></tr>').appendTo(scntDiv);
                i++;
                return false;
            });
        });
    function deleteRow(tableID) {
        var table = document.getElementById(tableID);
        var rowCount = table.rows.length;
        for(var i=0; i<rowCount; i++) {
                var row = table.rows[i];
                var chkbox = row.cells[0].childNodes[0];
                if(null != chkbox && true == chkbox.checked) {
                        if(rowCount <= 1) {                                                // limit the user from removing all the fields
                                alert("Cannot Remove all products.");
                                break;
                        }
                        table.deleteRow(i);
                        rowCount--;
                        i--;
                }
        }
}

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Can some one help me on this?