prevents you from doing that. 3. To disable the feature, simply disable the Prevent Overlaps check box. As mentioned earlier, this feature comes in handy when designing layer-based websites because it can prevent you from accidentally moving a layer above or below another layer. Nesting Layers Similar to the process of nesting tables within a cell of another table, layer nesting is the process of placing content in one layer within another layer. By default, Dreamweaver doesn't automatically nest layers; instead, Dreamweaver allows you to enable this option in the Layers category of the Preferences window. To enable layer nesting in your site, follow these steps: 1. Select the Preferences option from the Edit menu (or press Ctrl+U in Windows or Option+U on a Mac). The Preferences window appears. 2. Select the Layers category. 3. Enable the Nesting: Nest When Created Within a Layer check box. 4. Click OK. With that preference set, you can now create layers within other layers. For the most part, the process of nesting a layer within a second layer is as simple as drawing or inserting a layer within another layer. To do this, follow these steps: 1. Insert or draw a new layer on the page and name it BgLayer. 2. Select the layer and set the background color to gray by selecting a gray tone from the Bg Color field in the Properties Inspector. 3. Create a nested layer by inserting a new layer within the existing BgLayer layer. Name the new layer NestedLayer. 4. Insert a headshot image into the new NestedLayer layer so the result resembles Figure 11.10. Figure 11.10. Nest a layer within an existing layer. [View full size image] It won't be overly obvious that the new layer is nested within the BgLayer layer. However, you can see that the layer is in fact nested by looking at the Layers panel, also shown in Figure 11.10. As you can see, the NestedLayer layer appears as a child node beneath its parent BgLayer layer. The real benefit to nesting layers becomes evident when working with Visibility properties. Because the default Visibility property of a layer is Inherit, the child layer always inherits the properties of its parent layer. What this means is that all we have to modify is the parent BgLayer layer. Visibility changes made to this layer propagate down to all child layers, effectively saving us from doubling our efforts. Although it may seem obvious that dragging a nested layer out of its container layer would un-nest a layer, this is in fact not true. To un-nest a layer, you must use the Layers panel to drag a child layer out of its current position and reposition it higher in the Layers panel list. Deleting a Layer If you decide that a particular layer is no longer needed, you can easily delete it using one of three methods. The easiest way to delete a layer is to select it on the page and press the Delete or Backspace key on your keyboard. This action effectively removes the layer and its content from the document. Alternatively, select a layer from the Layers panel and press the Delete or Backspace key. Either method produces the same result. The third option for deleting a layer from the Document window is to right-click the <div> tag in the Tag Selector and choose the Remove Tag option from the context menu.