html - using jquery to replace text delete my span and his class -

i want replace text contained span class, code, thing happen span class deleted

here's code:

    $("input.textinput").on("keyup", function () {         target = $(this).attr("lang").replace("text", "div");         $("." + target).text($(this).val());     }); 

and here's example div:ì (before replace):

<div class="targetdiv"><span class="test"> text replaced </span></div> 

and how looks after script (after replace):

<div class="targetdiv">replacing text</div> 

edit

ok, here's fiddle:

http://jsfiddle.net/9xs9t/

you're directly targeting div, , calling .text() replaces entire content of div text.

change line:

$("." + target).text($(this).val()); 

to

$("." + target + " span").text($(this).val()); 

live example: http://jsfiddle.net/mtg9b/