router help needed ....urgent

Hi Techies....

I'm stuck in a problem....as i'm not very well with cisco routers...

I have a cisco router 1800 series with a 4 port fast ethernet card.
now i have attached both the internet isp's (A and B) over ethernet to
this router, now what i need is that all my traffic for internet from
lan A (192.168.1.0/24) should be routed to isp A and all from lan B
(10.220.16.0/24)should be routed to isp B.

Please ckick the link for the diagram. http://img248.imageshack.us/my.php?i...rawing1jq5.jpg

Thanks..............