problem with left and right background image position

[spectreman]

I'm trying to figure this out....

i want to add images to the right and left of my store, but i'm a little stumped.

looking at the css for http://www.naiah.fr/shop/

i see:

#flowersleft {
background:url(../images/myimagesL.png);
width:250px;
height:440px;
position:absolute;
left:4%;

}
#flowersright {
background:url(../images/myimagesR.png);
width:250px;
height:440px;
position:absolute;
right:4%;
}

i understand how it's calling the images, but if i copy the above to my css, the images don't show - what other PHP code do i need to change so the images show up?