Setting size of output image with print

[Søren Hauberg]

Hi,
  I'm doing something like this:
    image()
    print -dpng myimage.png
This gives me a nice 640x480 png image. Can I somehow set the size of 
the output image as I would like a larger output image? I'm using 2.9.10 
with gnuplot 4.2.

Thanks,
Søren