function preload(id)
{
    image = document.getElementById(id);
    hoverImage = new Image(); 
    hoverImage.src = image.src.replace("Off","On");
}

function showInit(id)
{
    image = document.getElementById(id);
    image.src = image.src.replace("Off","On");
    image.onmouseover = null;
    image.onmouseout = null;
}

function show(id)
{
    image = document.getElementById(id);
    image.src = image.src.replace("Off","On");
}

function hide(id)
{
    image = document.getElementById(id);
    image.src = image.src.replace("On","Off");
}