You also n
eed to change the routes on the ASA. In other words if you have
nat (inside) 1 xxx
global (outside1) 1 interface
nat (inside2) 2 yyy
global (outside2) interface
You will need to have 2 routes for different destinations. So for www you can use
route (outside1) www ....
And for zzz destinations
route (outside2) zzz
You cannot use 2 different ISP as the gateway simultaneously doing loab balancing because the ASA does not support it.
I hope it helps.
PK