The button object reflects the button element. While IE for the Mac doesn't share the sets of client- and scroll- properties with all element objects, those properties are defined for the button object. See the discussion of the button element in Chapter 8 to see how it differs from the input element of type button.

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.

Removes focus from the current object, at which time the object's onblur event fires. Note that the range of elements capable of focus and blur (both the event and method) is limited in all browsers except for more recent versions of IE (see the shared tabindex attribute in Chapter 8). Most reliably for backward compatibility, apply the blur( ) method to blatantly focusable elements, such as text input and textarea elements. Assigning the attribute onfocus="this.blur( );" to a text input element, for instance, is a crude but effective backward-compatible way to largely disable a field for browsers that do not provide genuine element disabling.

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.

Used with IE data binding to associate a remote data source column name to a button object's label. A datasrc attribute must also be set for the element. Setting both the dataFld and dataSrc properties to empty strings breaks the binding between element and data source.

Used with IE data binding, this property advises the browser whether the source material arriving from the data source is to be treated as plain text or as tagged HTML.

Used with IE data binding to specify the ID of the page's object element that loads the data source object for remote data access. Content from the data source is specified via the datafld attribute in the button element. Setting both the dataFld and dataSrc properties to empty strings breaks the binding between element and data source.

Specifies whether the element is available for user interaction. When set to true, the element cannot receive focus or be modified by the user, and it typically appears grayed out on the page. This property is available for all HTML element objects in IE 5.5 for Windows and later. For IE 4 and IE 5, it applies only to form controls, while Netscape 6 and later recognize the property for form controls and the style element object. A disabled form control's name/value pair is not submitted with its form.

Returns an array of all filter objects contained by the current element. Applies only to the following element objects: bdo, body, button, div, fieldset, img, input, marquee, rt, ruby, span, table, td, textarea, and th. See the filter object for referencing syntax.

Gives focus from the current object, at which time the object's onfocus event fires. Note that the range of elements capable of focus and blur (both the event and method) is limited in all browsers except for more recent versions of IE (see the shared tabindex attribute in Chapter 8). Most reliably for backward compatibility, apply the focus( ) method to blatantly focusable elements, such as text input and textarea elements.

Returns a reference to the form element that contains the current element (if any).

This is the identifier associated with the element when used as a form control. The value of this property is submitted as one-half of the name/value pair when the form is submitted to the server. Names are hidden from user view, since control labels are assigned via other means, depending on the control type. Form control names may also be used by script references to the objects.

Used with IE data binding, returns an integer representing the record within the data set that generated the element (i.e., an element whose content is filled via data binding). Values of this property can be used to extract a specific record from an Active Data Objects (ADO) record set (see recordset property). Although this property is defined for all IE element objects, the other properties related to data binding belong to a subset of elements.

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.

Unlike the status property of other types of form controls, the property has no visual or functional impact on the button.

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.

Specifies whether the button element is specified as a button, reset, or submit style button.

Provides the current value associated with the form control that is submitted with the name/value pair for the element. Unlike the button-type input element object, this value property's value is unseen by the user; the label is set by the element's content (innerHTML property or nested node).

Creates a TextRange object containing the button's label text. See the TextRange object.