I have purchached asus mother board M2N68-AM SE2 with AMD PROCESSOR but it have no sound

The board specifications on Asus' website indicates it includes a ALC662 High Definition Audio 6 -Channel CODEC. It may be possible that this board model comes with different options in different markets and does not come with onboard sound in your market. Check your regional Asus website or local dealer. If you need an audio driver, see the Download tab at the link above. Even if the board you have has the onboard sound hardware, a driver must be installed in whichever operating system you are using for it to work. The chipset driver may also need to be installed first so that all the board hardware is properly recognized by the operating system.