Window Geometry

/**
 * Geometry.js: portable functions for querying window and document geometry
 *
 * This module defines functions for querying window and document geometry.
 * 
 * getWindowX/Y(): return the position of the window on the screen
 * getViewportWidth/Height(): return the size of the browser viewport area
 * getDocumentWidth/Height(): return the size of the document.
 * getHorizontalScroll(): return the position of the horizontal scrollbar
 * getVerticalScroll(): return the position of the vertical scrollbar
 *
 * Note that there is no portable way to query the overall size of the 
 * browser window, so there are no getWindowWidth/Height() functions.
 * 
 * IMPORTANT: This module must be included in the <body> of a document
 *            instead of the <head> of the document.
 */
var Geometry = {};

if (window.screenLeft) { // IE and others
    Geometry.getWindowX = function() { return window.screenLeft; };
    Geometry.getWindowY = function() { return window.screenTop; };
}
else if (window.screenX) { // Firefox and others
    Geometry.getWindowX = function() { return window.screenX; };
    Geometry.getWindowY = function() { return window.screenY; };
}

if (window.innerWidth) { // All browsers but IE
    Geometry.getViewportWidth = function() { return window.innerWidth; };
    Geometry.getViewportHeight = function() { return window.innerHeight; };
    Geometry.getHorizontalScroll = function() { return window.pageXOffset; };
    Geometry.getVerticalScroll = function() { return window.pageYOffset; };
}
else if (document.documentElement && document.documentElement.clientWidth) {
    // These functions are for IE6 when there is a DOCTYPE
    Geometry.getViewportWidth =
        function() { return document.documentElement.clientWidth; };
    Geometry.getViewportHeight = 
        function() { return document.documentElement.clientHeight; };
    Geometry.getHorizontalScroll = 
        function() { return document.documentElement.scrollLeft; };
    Geometry.getVerticalScroll = 
        function() { return document.documentElement.scrollTop; };
}
else if (document.body.clientWidth) {
    // These are for IE4, IE5, and IE6 without a DOCTYPE
    Geometry.getViewportWidth =
        function() { return document.body.clientWidth; };
    Geometry.getViewportHeight =
        function() { return document.body.clientHeight; };
    Geometry.getHorizontalScroll =
        function() { return document.body.scrollLeft; };
    Geometry.getVerticalScroll = 
        function() { return document.body.scrollTop; };
}
'w=' + Geometry.getViewportWidth() + ' h='+ Geometry.getViewportHeight()