how do i get the motherboard output to work? mb is an Asus P4P800-VM. i plugged in my third monitor after getting a cable extension in the mail last night. didnt have much time to mess with it but i jumped into the bios config and didnt see anything in the onboard section... just lan and audio. there IS a vga port coming off of there. i opened the NVidia control panel for my 6800gt but then figured that it wouldnt work pushing 'detect displays' in there because it would just detect the two from the card, that are already working. so like, what do i do?