error: Unrecognized function or variable 'y', using ode45

this is my code and i get error: Unrecognized function or variable 'y', please help

function main

a = 0.01725*exp(2660/300);
E = 2660;
T0 = 300;
Cao = 2;
cpa = 20;
cpb = 20;
nao = 2*1200;
nbo = 2*1200;
b = (10*nao)/(cpa*nao+cpb*nbo);

[t,y]=ode45(@(t,y) DiabaticBatch(a,E,T0,Cao,b),[0 4000],[0 0]);


end

function dydt = DiabaticBatch(a,E,T0,Cao,b)

dydt = zeros(2,1);
dydt(1) = a*exp(-E/(T0+y(2)*b))*Cao*(1-y(1))^2;
dydt(2) = b*dydt(1);

end

Answer 1

[Walter Roberson]

function main

a = 0.01725*exp(2660/300);
E = 2660;
T0 = 300;
Cao = 2;
cpa = 20;
cpb = 20;
nao = 2*1200;
nbo = 2*1200;
b = (10*nao)/(cpa*nao+cpb*nbo);

[t,y]=ode45(@(t,y) DiabaticBatch(t,y,a,E,T0,Cao,b),[0 4000],[0 0]);


end

function dydt = DiabaticBatch(t,y,a,E,T0,Cao,b)

dydt = zeros(2,1);
dydt(1) = a*exp(-E/(T0+y(2)*b))*Cao*(1-y(1))^2;
dydt(2) = b*dydt(1);

end