Предложу такой вариант...
<!DOCTYPE html>
<html>
<head>
<!--
<script src="http://code.jquery.com/jquery-latest.js"></script>
<link rel="stylesheet" type="text/css" href="tmp.css" />
-->
<style type="text/css">
#source {
display: none;
}
</style>
<script type="text/javascript">
function add(Obj){
var frm=Obj.parentNode;
var o=document.getElementById('source');
o=o.getElementsByTagName('div')[0].cloneNode(true);
var i=frm.getElementsByTagName('div').length;
o.getElementsByTagName('span')[0].innerHTML=i+1;
frm.insertBefore(o,Obj);
};
</script>
</head>
<body>
<form action="" method="POST">
<input id="m" name="">
<div>
<p><span>1</span>. - </p>
<input name="">
<input name="">
<input name="">
</div>
<input type="button" onclick="add(this);">
</form>
<div id='source'>
<div>
<p><span></span>. - </p>
<input name="">
<input name="">
<input name="">
</div>
</div>
</body>
</html>