function Toggle(item)
{
    obj = document.getElementById(item);
    visible = (obj.style.display!="none");
    key = document.getElementById("x" + item);
    if(visible)
    {
        obj.style.display = "none";
        key.innerHTML = "<img src='images/plus.png'/>";
    }
    else
    {
        obj.style.display="block";
        key.innerHTML = "<img src='images/minus.png'/>";
    }
}
image1 = new Image();
image1.src = "images/plus.png";
image2 = new Image();
image2.src = "images/minus.png";