No graph - deterministic case

I expect that the following code gives a graph of y. But no graph is shown.
What am I missing? Can you help?

var y;
parameters a;

a=0.2;

model(linear);
y=a*y(-1);
end;

initval;
y=10;
end;

steady;

simul(periods = 50);

No, you need to add

after the simul command.

Thanks a lot!
Your help means a lot to me at this stage!