gift voucher problems !

Hi all !
searched about this problems and still no solution ! : for Opencart 1.5.3.
1- i want to set a gift voucher or certificate as payment option in my website , is there a method to figure this out ?
2-can customer use multiple voucher for purchasing one product ? (mean 20$+30$ for purchasing 50$ item ?
3-how can customer remove voucher code that already entered ?
4-total price problem ! when using gift code >>

waiting

no one ?!!

You can already do this with Open Cart. Multiple Vouchers can be used on the same total. Works fine.

how ? i mean you can enter 2 voucher code at the same time ! for example we have an item for 400$ and we have 2 vocher code (11111) = 100$ and another code (22222)=100$ , can this two be used at the same time and buy the product by these two ?

Thanks