Alternate boot option, use the interactive bootloader. Hold down Option prior to the chime, bootloader will read all interfaces and display all bootable volumes it found, optical drives included. Click to choose and click on green arrow.
If the optical disk you want to boot from doesn't show up, there are two possibilities: the SuperDrive ain't workin' or the disk you are insisting on using doesn't contain a bootable system the Mac can use.
Before the apple chime I press "option" and indeed it showed up the dvd drive but when I click the arrow choosing this as my start-up drive it will do rebooting but ednd up with just a white background & the gray colour apple logo. No information with regards to the content or anything happend except that it just display the apple logo.
That would mean that either the media can't be read withour error, or the system contained therein is incompatible with your Mac.
For example, I own a Snow Leopard upgrade box I bought when that cat came out. It contains a 10.6.0 system. However, my current Mac tries to boot from it and doesn't get past a white screen like you describe. It appears I would need a 10.6.5 or so as a minimum OS for it to boot, given my Mac's firmware.
If feasible, try booting off the media in another Mac.