I see two issues with your code:
1) By virtue of the fact that you have "while j <9" at the top, this implies that you expect that j will be changing somewhere inside the loop. But, as far as I can tell, j never changes. Therefore your loop is likely to execute an infinite number of time, or zero, depending on the initial value of j. You probably want to have a "j=j+1" somewhere in your loop, or maybe use "for j=1:9" instead.
2) You said the code stops at the second part, so I'm guessing that j starts out < 9, and that you expected it to continue. You have a "return" in the middle of the loop. Guess what return does? It stops the execution of the code right then and returns to the calling subroutine. If you want the code to keep going, just delete the return statement.
