The embed object reflects the embed element. Although the embed object is losing favor to the object element in recent browser generations, scripts in browsers such as Navigator 3, Navigator 4, and IE 4/Windows can control media players that load into a page in response to the embed element's pointer to a media file on the server. Properties and methods exposed by the player pass through the embed object so that scripts treat the embed object as if its list of scriptable powers is extended. Properties listed here are the properties that the element object, rather than an external controller, exposes to scripts.

This is single character key that either gives focus to an element (in some browsers) or activates a form control or link action. The browser and operating system determine if the user must press a modifier key (e.g., Ctrl, Alt, or Command) with the access key to activate the link. In Windows versions of IE 5 and later and Netscape 6, the Alt key is required and the key is not case-sensitive. For Macintosh versions of IE 5 and later and Netscape 6, the Ctrl modifier key is required to effect the action.

Defines the alignment of the element within its surrounding container. See the Section 8.1.5 at the beginning of Chapter 8 for the various meanings that different values bring to this property.

Broadly speaking, these provide the height and width of the element's content, but with minor variations with respect to element padding among various operating system versions of IE and compatibility modes controlled by the DOCTYPE declaration. Not available for all element types in IE for Macintosh. For Netscape 7, values are zero except when an element's content overflows the viewable area, in which case the values reveal the dimensions of the viewable area (e.g., the browser window's content region for the document.body element). See the Section 9.2 at the beginning of this chapter for details.

Broadly speaking, these provide the left and top coordinates of the element's content within the box that includes the element's padding, but with minor variations among various operating system versions of IE. Not available for all element types in IE for Macintosh. See the Section 9.2 at the beginning of this chapter for details. More useful information for inline element positioning generally comes from the offsetLeft and offsetTop properties (including Netscape 6). For CSS-positioned elements (including changing an element's position), use style object properties, such as left and top, and (in IE only) pixelLeft and pixelTop.

Provide the height and width in pixels of the element as set by the tag attributes. Changing the values does not necessarily change the actual rectangle of the applet after it has loaded.

Specifies whether the embedded data's plugin control panel appears on the screen. Changes to this property force the page to reflow its content to make room for the plugin control panel or close up space around a newly hidden panel.

Reflects the name attribute value of the element's tag.

Returns the setting of the palette attribute of the embed object.

Indicates the URL for downloading and installing the plugin necessary to run the current object's embedded data.

Returns the current download status of the object's content. If a script (especially one initiated by a user event) can perform some actions while the document is still loading, but must avoid other actions until the entire page has loaded, this property provides intermediate information about the loading process. You should use its value in condition tests. The value of this property changes during loading as the loading state changes. Each change of the property value fires an onReadyStateChange event (the event does not bubble).

Originally implemented in IE 4 for elements that either scrolled or influenced an element's scroll (body, button, caption, div, fieldset, legend, marquee, and textarea), these properties return the pixel dimensions of an element, including elements that are larger than the viewable area in the browser window. This is in contrast to the clientHeight and clientWidth properties for scrollable elements, which return dimensions of only visible portions of the element. IE for the Macintosh, however, interprets the intent of the scroll- properties differently, returning the dimensions of the visible portion.

Provide the distance in pixels between the actual left or top edge of the element's physical content and the left or top edge of the visible portion of the content. Setting these properties allows you to use a script to adjust the scrolling of content within a scrollable container, such as text in a textarea element or an entire document in the browser window or frame. When the content is not scrolled, both values are zero. Setting the scrollTop property to 15 scrolls the document upward by 15 pixels in the window; the scrollLeft property is unaffected unless explicitly changed. The property values change as the user adjusts the scrollbars. This is important for some event-driven positioning tasks in IE for Windows because the coordinate system for event offset measurements are with respect to the visible area of a page in the browser window. You must add document.body scrolling factors to align event coordinates with body content positions (see the element dragging example in Chapter 6). Starting with IE 5 for Windows, the scrollLeft and scrollTop properties are available for all HTML element objects, but values for unscrollable elements are zero.

Indicates URL of the external content file associated with the object. Although some controllers may respond to changes of this attribute, it is more reliable to load a different file into the controller via its own loading method or property.

This is a number that indicates the sequence of this element within the tabbing order of all focusable elements in the document. Tabbing order follows a strict set of rules. Elements that have values other than zero assigned to their tabIndex properties are first in line when a user starts tabbing in a page. Focus starts with the element with the lowest tabIndex value and proceeds in order to the highest value, regardless of physical location on the page or in the document. If two elements have the same tabIndex values, the element that comes earlier in the document receives focus first. Next come all elements that either don't support the tabIndex property or have the value set to zero. These elements receive focus in the order in which they appear in the document.

Indicates the MIME type of the external data assigned to the element's type attribute.

Specifies the unit of measure for the height and width dimensions of the element. Internet Explorer appears to treat all settings as pixels.

See height.