Cross Browser dHTML functions

1. Get the .js file here.
2.
//-------------------------------------------------------------------------------------------
// dHTML functions
//
// IE and Firefox compatible dHTML functions
//  Copyright 2008 James McGowan (jamesweb 'at' bampotty 'dot' com)
//
// Not to be used without the author's permission.
//
//-------------------------------------------------------------------------------------------
// usage :
//
// <script src="dHTML.js" type="text/javascript" language="javascript"></script>
//
// <script>
// var a = new dHTML();
// var x = a.screenWidth();
// a.setXById("div1",200);
// a.centerById("div2");
// if (a.isIE()) { alert("IE"); } else { alert("Firefox"); }
// <script>
//
//-------------------------------------------------------------------------------------------
// summary of methods
//
// .isIE()                 - true or false if the browser is IE or not.
// .screenWidth()          - available frame/window width in pixels
// .screenHeight()         - available frame/window height in pixels
// .Div(name)              - takes a name and retuns the div
// .setX(div,px)           - set the x-coordinate of a screen element
// .setY(div,px)           - set the y-coordinate of a screen element
// .setXById(id,px)        - set the x-coordinate of a screen element identified by ID
// .setYById(id,px)        - set the y-coordinate of a screen element identified by ID
// .getX(div)              - get the x-coordinate of a screen element
// .getY(div)              - get the y-coordinate of a screen element
// .getXById(id)           - get the x-coordinate of a screen element identified by ID
// .getYById(id)           - get the y-coordinate of a screen element identified by ID
// .getWidth(div)          - get the width of an element in pixels
// .getHeight(div)         - get the height of an element in pixels
// .getWidthById(id)       - get the width of an element identified by ID in pixels
// .getHeightById(id)      - get the height of an element identified by ID in pixels
// .center(div)            - centre a screen element on the available screen
// .centerById(id)         - centre a screen element identified by ID on the available screen
// .createDiv(name,html)   - creates a new floating div