adding a row to a matrix with variable

[Rich]

Hi,

Is it possible to add a row to a matrix that has a variable in it?

I am able to add a row to a 2x2 matrix using this

addrow(a1,[1,3],2) resulting in [[0,0],[1,3]]

If i add a variable to to the line (example below) it gives me a "Error bad argument type"? I am trying to set the variable as a real or integer, but I am still getting the same results.

addrow(a1,[1,k],2) resulting in "Error: Bad argument type"

EDIT:: Initially a1:=[[0,0]]

Thank you,