core/api/modules/cart/mod.js

$(".change-kolvo").keyup(function(event){
    var id=$(this).data('id');
    var kolvo=$(this).val();
    $.ajax({
      type:"POST",
      url:'/act/cart',
      data:"act=change-kolvo&kolvo=" + kolvo + "&id=" + id, 
      success:function(data){$("#summ").text(data)}
    });
  })
  //удалялка
  function deleteFromCart( id, summ ){
    $( "#div-" + id ).hide( 600 );
    $( "#summ" ).text( summ );
  }
    

  $( ".a-del-from-cart" ).click( function( event ){
    var id = $(this).data( 'id' );
    $.ajax({
      type:"POST",
      url:'/act/cart',
      data:"act=del-from-cart&id=" + id, 
      success:function(data){ deleteFromCart( id, data ) }
    });
    return false;
  })