Surely you should have learned by now (having asked 19 questions on Answers), that if you just need to assign a value like 141 to a variable, you do not need to use a for statement? All these lines do is assign the value 141 to j, and 41 to i.
for j=141
for i=71
And worse, because you have created for loops, you then need to have end statements too. Just do this:
j = 141;
i = 41;
