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.body && document.body.clientWidth) {
    // These functions are for IE6 when there is 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; };
}
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; };
}

// These functions return the size of the document.  They are not window 
// related, but they are useful to have here anyway.
if (document.body && document.body.scrollWidth) {
    Geometry.getDocumentWidth =
        function() { return document.body.scrollWidth; };
    Geometry.getDocumentHeight =
        function() { return document.body.scrollHeight; };
}
else if (document.body.scrollWidth) {
    Geometry.getDocumentWidth =
        function() { return document.body.scrollWidth; };
    Geometry.getDocumentHeight =
        function() { return document.body.scrollHeight; };
}