I have three background images for a button - left.png, center.png and right.png. The left and right ones have rounded edges and the center one is a single line which need to extend based on the size of the button. How do I create such a button? I have considered the option of constructing the image on the fly and apply it to the button in the resize event, but am looking to see if this is possible through stylesheets. Is this possible?