How2: gray install DVD to USB

[adam9c1]

I have 10.6.3 original DVD I want to put on flash drive bootable.

Went to disk until and did a restore from DVD to flash drive.

I see the drive in boot options but after a while I get the crossed circle.

 

[adam9c1]

I made a .dmg of the installer DVD. Then from the DMG I restored to USB bootable.