<body>
<script src="//code.jquery.com/jquery.min.js"></script>
<script>
var form= '<form class="form">'+
'<input type="text" id="text" />'+
'<input type="submit" value="Сохранить" />'+
'</form>';
$('body').append(form);
$('.form').fadeIn(400);
$('#text').focus();
</script>
</body>