Hello ,
how i can make the power on/off for any project by two push button, one for the (on) and the other for the (off).
anyone have an idea??
Two-coil latching relay.
Use a two coil latching relay and have the buttons fire each relay state.
Hi,
You could use a relay. It will need a Normally Open Button and a Normally Closed Button
There are also some MOSFET versions as well.
Tom... 
THANK YOU ..
The simplest solution is a ganged push-button switch. Such as this: http://www.mouser.com/ProductDetail/Switchcraft/65021K206/?qs=VpI5ComNerRMY5q4WEsCRA%3D%3D.
Paul