Optimization of machining parameter using genetic algorithm.

My project tittle is optimization of machining parameter using gene tic algorithm. This is equation,and i need to find out x1 and x2

x1 range from 60<x1>120 and x2 range from 0.05<x2>.4

y=(Cl+Co)*(3.14*d*K/1000*z)*(1/x1)*(1/x2))+(Ct)*(3.14*d*K*Q*5^(g/n))/ 60000*z*(C^(1/n))*(a^(g-w)/n)*(x1^(1/n)-1)*(x2^((w+g)/n)-1)/ 60*(1/Q)*(C^(1/n))*(5^(-g/n))*(a^(g-w)/n)*(x1^-(1/n))*(x2^-(w+g)/n);

This are the constant values

K=450; a=10; d=50; z=6; Ct=49.50; Cl=.45; Co=1.45; Q=(15/25); w=.28; g=.14; n=.15; C=33.98

 plz help me out to write the program...