Well I thought this worked Linda however in practice it doesn't ... I issued the SQL query UPDATE products SET products_quantity_mixed=0; which should in theory stop people buying odd amounts . For example I need people to buy a product in lumps of 12 and other products in lumps of 25, and although I can set the amount that people can buy in the shop if someone adds say 13 items to the cart the cart lets them through to checkout, I don't want this. The buyer must buy either 12 or 24 or 36 or 48 etc, ie multiples of 12 I cannot see anyway to make the cart do this ? The same is true for items of 25 they must be sold in lumps of 25, ie 25, 50, 75, not 26, 27 or 35 etc.

So to sum up some items need to be sold in quantities of, and I would also like to be able to modify categories rather than individual items as this way of modifying items will take me days of tedious individual pricing. Please help if you can, thanks.