Question: Index out of bounds in procedure

Hi there,
I have a simple task to do with arrays. I have an 8x3000 array, whose columns are sometimes all zeroes (if any element in the column is zero then the entire column is zero). I want to eliminate the zero vectors, so I have this loop (the array is A)

for i from 1 to 3000 do
    while A(1,i)=0 do
        A:=DeleteColumn(A,i);
    end do;
end do:

Setting "A:=DeleteColumn(A,i);" reduces the size of the array, so if all the zero columns have been deleted at "i=200", Maple will keep trying to check the next column, which doesn't exist anymore. This gives an "index out of bounds" error, but also records "A" as the new smaller array, which is fine.

If I run this loop inside a procedure, the error stops the procedure, but it doesn't record the new array, it stays as the older, larger one. Does anyone know of a way around this?

Any help would be much appreciated.