成功的AJAX调用后，跨度值更改回旧值

So I have this one weird situation which I am really confused now. I can't see any solution on the Net yet for this weird issue. I have one AJAX call that will populate the data which generated on the page also by using AJAX (dynamic). Here is my code:

My jQuery Code:

$(document).delegate('.edit_tr', 'click', function(){
    var the_id = $(this).attr('id');
}).delegate('.edit_tr', 'keypress', function(e){
        if(e.which == 13) {
            var input_name = $("#input_name_" + the_id ).val();
            if(input_name.length > 0){
                //if I reset the span text and do return false here, the text showed properly on the page
                $.ajax({
                    type: "POST",
                    url: "ajax_update.php",
                    data: data_string,
                    success: function(html){
                        //do the reset of span text
                        $('#name_'+the_id+'').html(input_name);
                        alert('Examining'); //while alert is popped up,text of span is expected as changed
                        //after 'OK' is clicked on the alert, the span text go back to its previous text
                     },
                    error: function(err){
                        //do something
                    }
                });
             }
         }
    });

Code in another PHP page which gets called via AJAX. This page displays the data on the page before being manipulated by above code for edit in place.

$returned_msg .= '<form id="form1">';

if( $contact_details->exists() ){
    $lists = $contact_details->data();

    foreach( $lists as $list ){
        $returned_msg .= '<tr id = "'.$list->cont_detail_id.'" class="edit_tr">
                            <td style="text-align:center"  class="edit_td">
                                <input type="hidden" value="'.$list->cont_detail_id.'" id="cont_detail_id_'.$list->cont_detail_id.'" />
                                <span id="name_'.$list->cont_detail_id.'" class="text_span">'.$list->det_name.'</span>
                                <input type="text" value="'.$list->det_name.'" style="width:120px;height:6px;" class="editbox" id="input_name_'.$list->cont_detail_id.'" />
                                <input type="hidden" value="'.$list->det_name.'" class="editbox" id="hidden_name_'.$list->cont_detail_id.'" />
                            </td>
                        </tr>';
    }

    $returned_msg .= '</form>';

}

class editbox is not displayed till the tr is clicked. I am now totally baffled. Looking forward to get some thought on what could probably causing this. Thank you.