Error with ODE and nargin

Hello, can anyone help me out with this.?

function xdot = glucoseff(t,x)

p1=0.028735;

p2=0.028344;

p3=5.0353e-5;

gb=200;

ib=0;

n=0.10;

vi=12;

a=0:0.1:10

ug=exp(-a);

g=x(1);

y=x(2);

i=x(3);

%

%odes

%

dgdt=(-p1*g)-(t*g)+(p1*gb)+ug;

dydt=(-p2*y)+(p3*i)-(p3*ib);

didt=(-n*i)+ui/vi;

xdot = [dgdt; dydt; didt];

end

clc;

x0=[200;0;10];

[t,x] = ode45('glucoseff',[0 10],0);

plot(x(:,1));

plot(x(:,2));

plot(x(:,3));

I don't understand the error :

Error using nargin

Error: File: glucoseff.m Line: 1 Column: 1

Function definitions are not permitted in this context.

Error in odearguments (line 60)

if (nargin(ode) == 2)

Error in ode45 (line 115)

odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);

Error in glucose_main (line 4)

[t,x] = ode45('glucoseff',[0 10],0);

[Alan Stevens]

1. You need to define ui within glocoseff.
2. Do you really want ug to be a vector the same size as a; or do you want it to take on the different a values one at a time?

[VBBV]

 % if true
    % code
  %end
[t,x] = ode45(@glucoseff,[0 10],x0)

[Divya Noonela]

ug is a vector of same size of a