$("body").on('click', ".add-to-cart", function(e) {
            e.preventDefault();
            $.ajax({
            beforeSend: function( xhr ) {
                $('.overlay-1').show();
            },
            url: 'add_to_cart',
            data: {id:'itemId'},
            headers: {
                'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
                }
            }).done(function(mes) {
                console.log(mes);
            });


         });

// PHP
1. if(available_goods_with_id_of_id>1){
	available_goods_with_id_of_id--;
}
return 'success';

         $("body").on('click', ".remove-from-cart", function(e) {
            e.preventDefault();
            $.ajax({
            beforeSend: function( xhr ) {
                $('.overlay-1').show();
            },
            url: 'remove_from_cart',
            data: {id:'itemId'},
            headers: {
                'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
                }
            }).done(function(mes) {
                console.log(mes);
            });


         });

// PHP
1. available_goods_with_id_of_id++;
return 'success';