Inserting a row into a matrix?

[JazzyJeff123]

I'm writing a function that inserts a row into a matrix and deletes the last row.

But I'm having trouble. What do I need to add to this function:

[JazzyJeff123]

So the first column has to look like
2
3
4
5
6
7
8
The Row with the 4,8,12.... shouldn't be deleted.