... First the chapter gives an overview of why you might want to use JavaScript to modify blocks of content, then it discusses the Layer object, which represents a block of content. ... The Layer Object . ... Each document object has a layers property that contains an array of all the top-level layers in the document. ... You can use JavaScript to create new layer objects by calling the new operator on a Layer object, for example: bluelayer = document.bluelayer; newbluelayer = new Layer(300, bluelayer);...