I was thinking it would be very handly if having a merchant account would be possible to autogenerate some number and send it with the pre auth message to customers card statement. Just like paypal does when u want to verify your credit card. PayPal somehow does not charge but put a hold on $1.95, a kind of pending payment but it apears in the statement and only clear the funds when the code is entered on the website. U can also send this number when shipping merchandise or gerenate 2 numbers: 1 for card statement and 1 for merchandise so u can insta lock the amount with pre auth but clear the funds only when these 2 codes are entered on the webside. That would reduce chargebacks alot i guess becouse merhant will only clear when hes sure that it was not a fraud payment and merchandise delivered. Also there could be something in the ToS that by entering the code you received with merchandise u aggre that product was exactly as explained on the webside and not damaged.

Any ideas?

It does on the merchant side. Your software may do it. But you will pay transaction fee for both transacations. Also, some banks don't show pre-authorized amount in statements neither online ones nor hardcopy ones.
So, you will have to make charge transactions to make your charges visible to your clients on their statements.

It sounds like you are wanting to doa pre-authorization? If so, it could be good but another problem, these pre-auths are usually only good for a certain amount of time (depending on the issuing bank).

The times are usually 3-10 business days that they money is guaranteed yours. There are times also where you can actually do the post-authorization / sale on a pre-auth a couple of months down the road and the money is yours.