How can I display graphs without a background or axes?

Basic question here.

The default settings are such that each time I type "newImage" an image is displayed along with an x and y axis. To remove these axes, I used the commands:

ModifyGraph noLabel(left)=2,axThick(left)=0
ModifyGraph noLabel(top)=2,axThick(top)=0

However, I am still left with a white background. What command can be used to make the image fill the window entirely?