CSS Filter + background image

could you merge css filter class with a background image that will tile together?

example: i create a filter class that goes from black to white and apply to the body of the html page but i also want to apply 5x5 pixels background image and merge them together in one page, so that my 5x5 image would fade from black to white

also

filter class works only in IE, does anyone know any alternative way to make it work in FF?