You could easily do it with a PIC (which would make you component count VERY! low). However, you can easily use a couple of 555 timers and a handful of components to do it, try googling for "servo tester" - it's a VERY common project!.
Thank you for the reply,
I've been googling the words you said but i can't found exacly what I need.
yes I fount the tester using 3 bottons, left, center and right.
but since I'm not electrnic person I can't modify using 1 single push botton to do left and if I press again it will rotate right.
this is what I want.
there are plenty of toggle circuits using CMOS chips in the forum.
just add one more inverter to this and make sure to connect upper side of potentiometers through diodes to outputs of toggle circuit.
**broken link removed**
sorry, no time... you can forget the toggle circuit and just use maintained button. connect common to +V, NC to one pot (set closed position), NO to another (set open position). you could replace sw. contacts with outputs from another circuit.