There are some other techniques for programming with images besides those that use the Image object discussed here. We saw one, the dynamic generation of XBM images, in Chapter 14, Documents and Their Contents. There is another technique that can be useful when dynamically generating documents (in another window or frame) that contain images. Bear in mind that if the image you supply does not match the WIDTH and HEIGHT specified in the <IMG> tag, the browser will stretch the image as necessary. This can be useful, for example if you want to use an image as a graphical horizontal rule: you can supply an image that is only one pixel wide (that will thus load quickly), and rely on the browser to stretch it horizontally for you to any desired length.