Newton-Raphson Method for 2 variables

Newton method for non-linear system of 2 variables (also solves linear system)

This program calculates the roots of a system of non-linear equations in 2 variables. This a script file and you only have to write in the command windows ">>newton2v2", and the program ask for the functions and other elements that are necessary. What I mean "quotes" is single quotes,like this: ' .
I will be grateful for any comment.
I also have this program for 3, 4 ,5 variables and can be extended to any number of variables