document.images[i] document.images.length document.image-name
The images property of the Document object is an array of Image objects, one for each image that is embedded in the document with the HTML <IMG> tag.
If the NAME attribute is specified in the <IMG> tag for an Image, then a reference to that image will also be stored in a property of the Document object. This property will have the same name as the image. So if an image has a NAME="toggle" attribute, then you can refer to the image with document.toggle.