stock levels

the stock levels on my website go a little *wonky* over time - I have no idea how it happens I just think that the website can't add or subtract in a normal way - it would never pass a maths exam, that's for sure!

example question: you have 120 red polka dot buttons in stock, you sell 46 - how many red polka dot buttons do you have left?  my websites answer: 52 (or any other random number it can think of!)

 

 Some of my stock items were marked as zero even though I had some and some said I had loads when I had none at all !!!

 So I spent some time today counting and sorting and refilling existing stocks with new deliveries...the website has all the correct stock levels entered and we shall see how it goes!