防止输入量在JQuery中变为负数

I have a feature on my current site that increments and decrements a value when you click the plus button or the minus button. Since it's on an ecommerce site as an order quantity, it doesn't make a whole lot of sense to have an option for the value to be negative. I was trying to add some logic to my jquery that would prevent the value from becoming negative but my nested logic wasn't working for some reason. Any help would be much appreciated!I have a feature on my current site that increm