Lu decomposition help needed

this is as far as i have got can anyone help me?

function [L,U] = LUdecomp(A)

n = size(A,1); %number of rows

m = size(A,2); %number of cols

% Check to see if the input matrix is a square

if n~=m

error('The input matrix is not square')

end

U = A; %The U matrix will be what is left after G.E. with the matrix A

L = eye(n); %The L matrix will be what is left after G.E. applied to the identity matrix

for i = 1:n-1 %i is the current column that you are trying to create zeros for in U

for j = i+1:n %j is the current row that you are trying to create the zero in