Plot a line passing through two points to the axis

[Victor Semanic]

Hello: I am plotting a line in Octave by having the line run through two points.
Here are the commands:

octave:3> axis([-1,1,-1,1])
octave:4> hold on
octave:5> plot(2*rand(1,2)-1, 2*rand(1,2)-1)

The line plots fine.  However, I want to extend the line such that it touches
the x and y axes.  When the points in the plot() command are nearby
each other, the line is short.  What I want to do is to extend the line such
that it touches the axes.

Can anyone suggest how to do this?  I would appreciate it very much.

Thank you so much.