No line spacing when using drawline

Hmmmmmm, major error on my part :-(

My code from the emulator:

g.clear();

// fill screen with green
g.setColor(0,1,0);  // green
g.fillRect(0,0,239,239);

// reset getModified area
m=g.getModified(true);

print(m);

g.setColor(1,0,0);  // red

// g.fillRect(100,100,120,120);

m=g.getModified();

print(m);

g.clearRect(m.x1,m.y1,m.x2,m.y2);

Output is:

>{ "x1": 0, "y1": 0, "x2": 239, "y2": 239 }
>undefined
>Uncaught Error: Cannot read property 'x1' of undefined
 at line 20 col 14
g.clearRect(m.x1,m.y1,m.x2,m.y2);
             ^
>

I see now dat getModified(true) returns an undefined. I was completely mislead by the response >{ "x1": 0, "y1": 0, "x2": 239, "y2": 239 } and assumed that this was the area that was set.

Apologies for wasting your time (red face), appreciate the help.