[Deff]

<script src="http://code.jquery.com/jquery-latest.js"></script>

<a class="lnk_red_u DoubleClickUpdate" style="text-decoration: none;" href="/product-302-alcatel.html" href1="index.php?do=usercp&amp;go=nck&amp;select=request&amp;productid=302">Alcatel</a>


<script>
$('.DoubleClickUpdate').click(function() {
          var b=$(this);b.toggleClass('Nodb');
          setTimeout(function() {b.removeClass('Nodb');},500)
          if(!b.hasClass('Nodb')){clearTimeout(timeout_id0);alert('Тут двойного!')}
          if(b.hasClass('Nodb')){timeout_id0 = setTimeout(function() {alert('Тут функция одиночного клика!')},500)}
          return false; 
        });
</script>