How to draw graph with both axis labeled with different scale

[Linghui Han]

My code:

twoway (scatter state year, sort by(province)) (scatter wagepre year, sort yaxis(2) by(province)) (lfit state wagepre), ytitle(State employment %) ytitle(Wage premium) xtitle(Year) xlabel(1951(10)2014) legend(order(1 "State employment" 2 "Wage premium" ))

does not work.