How can I put my ruler origin in the left upper corner of my workspace and make an artboard?

I want to put my ruler origin to the upper left corner of my workspace so I can make an artboard that covers the whole workspace. If I do it with the code I have now it just put the ruler at the origin of the first artboard I have, but I don't know why. And if I can put the ruler to the upper left corner by javascript(not by hand) does somebody know how I can create an artboard that covers my whole workspace? 16383 is the maximum size of the workspace in points.

myDoc = app.activeDocument; 
myDoc.rulerOrigin = [0,myDoc.height];
 
var rect = rect(0, 0, 16383, 16386);
var myArtB = myDoc.artboards.add(rect);
 

function rect(x, y, w, h) {
    return [x, -y, (x + w), -(y + h)];
}