Notes: You can add a background (BG image ) to the banner APdiv2 using the CSS Property editor. Click on the APdiv2 so you can see the blue out-line with drag and expand points.... The graphic, if it's a photo should be the same size as the div. The size of the div can be seen in the properties dialogue box. (995 x 148 pixels)... If you click inside the box that says apDiv2, you can rename it "banner"...
If the graphic is a gradient it might look like this
It's a gradient graphic 1 pixel wide and 200 pixels tall... 
and inside an APdiv the same gradient graphic can looks like this... The graphic or image automatically repeats in the x and y direction to fill the container it is in...
This lighter part is the gradient repeating...