[Tiia, Finland]

I'm trying to add two colors to the background of my document so that it
would gradually change from one to the other (from top to bottom). However,
when I do this, I only get a wavy pattern in wich the colors change back and
forth.
I tried creating a .jpg-file and attaching it as a background to the
document. This resulted in a background where the picture is displayed
several times so that it fills the entire page.
So my question is, how can I get the picture stretched to fit the page?
And is the same option available for the background colors so that the color
would change only once over the entire page (from top to bottom)?