/**
Image rollover. SGR Engineering Ltd. (c) 2006. www.sgrisp.co.uk

Call the preloader once for each button at the start of the body, using its label and alternate image source

Use <a href="html.html" 
       onMouseOver="rollover('home')" 
       onMouseOut="rollout('home')">
       <img name=label src=src></a> 
       
Call the preloader once for each button, using its label and alternate image source
 */
var rollOverArr=new Array();
var preloadArr=new Array();

function preloadRollover(ImgSrc,ImageLabel)
{
if (! document.images)return;
if (! ImgSrc)return;
if (! ImageLabel)return;
rollOverArr[ImageLabel]=new Object;
rollOverArr[ImageLabel].overImg = new Image();
rollOverArr[ImageLabel].overImg.src=ImgSrc;
preloadArr[ImageLabel] = new Image();
preloadArr[ImageLabel].src = ImgSrc;
}

function rollover(ImageLabel)
{
if (! document.images)return;
if (! rollOverArr[ImageLabel])return;
if (! rollOverArr[ImageLabel].outImg)
    {
    rollOverArr[ImageLabel].outImg = new Image();
    rollOverArr[ImageLabel].outImg.src = document.images[ImageLabel].src;
    }
document.images[ImageLabel].src=rollOverArr[ImageLabel].overImg.src;
}

function rollout(ImageLabel)
{
if (! document.images)return;
if (! rollOverArr[ImageLabel])return;
document.images[ImageLabel].src=rollOverArr[ImageLabel].outImg.src;
}