Editor error

I am new to Matlab (student) and I am trying to run this (below) in the command window after typing it as an M-file.

n=25;


a = round(linspace(1000,9999,n));

b=round(randn(n,1)*17+68);

c=round(randn(n,1)*15+75);

d=round(randn(n,1)*19+82);

Do you have any suggestions for this isn't running. It keeps giving me an error about an illegal input?

Thank you,
ld