how to overcome matrix dimensions must agree error

I have attached the screen shot taken from coding pls help to solve this issue.

[Image Analyst]

Please copy the entire error message, and the code. All I can say now is that you're doing some kind of matrix operation that is not allowed, like trying to stuff a bunch of elements into one element, or trying to multiply a r1xc1 matrix by a r2xc2 matrix where c1 is not equal to r2.