<div class="chet"></div><div class="chet"></div><div class="chet"></div>
<div>тут кол-во div</div>
<input id="tyt" type="text" value="">
<!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"> </style> <script type="text/javascript"> $(document).ready(function (){ var n=$('.chet').length; $('#d_n').text(n); $('#i_n').val(n); }); </script> </head> <body> <div class="chet">Item 1</div> <div class="chet">Item 2</div> <div class="chet">Item 3</div> <div id="d_n"></div> <input id="i_n" type="text" /> </body> </html>