jquery clone an html structure with out text content

jquery clone an html structure with out text content

every one. please help me.
how to clone an html structure ( with tables and input field ) without its
input content.
this is my html code
<div class="clone_wrapp">
<div class="clone_table">
<div class="two_column_table">
<table>
<tr><td>Name of officer-in-charge</td></tr>
<tr><td><input type="text"></td></tr>
<tr><td>Contact No</td></tr>
<tr><td><input type="text"></td></tr>
</table>
</div> <!-- two_column_table -->
<div class="two_column_table">
<table>
<tr>
<td>Address</td>
<td><textarea></textarea></td>
</tr>
</table>
</div> <!-- two_column_table -->
</div> <!-- clone_table -->
</div> <!-- cloned wrapp -->
<div class="add_more_field">ADD MORE</div>
and this is my jquery
$('.add_more_field').click(function(){
var cloned_structure= $('.clone_table').clone();
$('.clone_wrapp').append(cloned_structure);
});
the code is working but it will append along with input content
thanks