urgent.how to do raid of raid

Hello Everybody,
Im trying to setup RAID 1+0 using four scsi devices..
Im using RHEL3......

Im able to set up RAID 1 on the four scsi devices( sda,sdb,sdc,sdd)
....ie

---> /dev/md0
------------------------> /dev/sda1
------------------------>/dev/sdb1

-----> /dev/md1
------------------------>/dev/sdc1
-------------------------> /dev/sdd1

Now, I want to create a RAID 0 of /dev/md0 and /dev/md1

Is it possible..if yes then how...Its the first time im setting
RAID......
Any help will be appreciated...

Thanks
Danish

.