caption | NN 6 IE 4 DOM 1
The caption object reflects the caption element, which must always be nested inside a table element. IE/Mac implements the client and scroll property sets for this object.
HTML Equivalent
    <caption>
Object Model Reference
    [window.]document.getElementById("elementID")
Object-Specific Properties
align | vAlign
Object-Specific Methods
None.
Object-Specific Event Handler Properties
None.

align | NN 6 IE 4 DOM 1
| Read/Write
Determines the position of the caption in the table. See the align attribute of the caption element in Chapter 8 for details on the interaction between the align and vAlign attributes and properties in IE for Windows. The W3C DOM uses the align property predominantly for placing the caption above or below the table.
Example
    document.getElementById("myCaption").align = "bottom";
Value
Any of the following constants (as a string): bottom | left | right | top.
Default
top

blur( ) | NN 2 IE 3 DOM 1
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.
Use blur( ) and focus( ) methods in moderation on the same page. You can inadvertently trigger endless loops of blurring and focusing if alert dialog boxes are involved along the way. Moreover, be aware that when you invoke the blur( ) method on one object, some other object (perhaps the window object) receives an onfocus event.
Parameters
None.
Returned Value
None.

clientHeight, clientWidth | NN 7 IE 4 DOM n/a
| Read-only
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.
Example
    var midHeight = document.body.clientHeight/2;
Value
Integer pixel value.
Default
0

clientLeft, clientTop | NN n/a IE 4 DOM n/a
| Read-only
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.
Value
Integer pixel value.
Default
0

focus( ) | NN 2 IE 3 DOM 1
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.
To give a text box focus and pre-select all the text in the box, use the sequence of focus( ) and select( ) methods on the element. If this sequence is to occur after windows change (such as after an alert dialog box closes), place the methods in a separate function, and invoke this function through the setTimeout( ) method following the alert( ) method for the dialog. This allows IE/Windows to sequence statement execution correctly.
Parameters
None.
Returned Value
None.

scrollHeight, scrollWidth | NN 7 IE 4 DOM n/a
| Read-only
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.
Starting in IE 5 for Windows, all HTML elements have these properties, and the values for nonscrolling elements are the same as the offsetHeight and offsetWidth properties. Netscape 7 implements these properties for all elements, returning the height and width of the element, whether or not it's in view. The important point is that for key elements, such as the body, the properties mean different things and can disrupt cross-platform operation.
Example
    var midPoint = document.body.scrollHeight/2;
Value
Positive integer or zero.
Default
None.

scrollLeft, scrollTop | NN 7 IE 4 DOM n/a
| Read/Write
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.
Example
    document.body.scrollTop = 40;
Value
Positive integer or zero.
Default
0

vAlign | NN n/a IE 4 DOM n/a
| Read/Write
Specifies whether the table caption appears above or below the table.
Example
    document.getElementById("tabCaption").vAlign = "bottom"
Value
Case-insensitive constant (as a string): bottom | top.
Default
top