function hideDivs()
{
    var el;
    el = document.getElementById("div1")
    el.style.display="none";
    el = document.getElementById("div2")
    el.style.display="none";
    el = document.getElementById("div3")
    el.style.display="none";
    el = document.getElementById("div4")
    el.style.display="none";
    el = document.getElementById("div5")
    el.style.display="none";
    el = document.getElementById("div6")
    el.style.display="none";
}
function showDiv(id)
{
    hideDivs();
    var el;
    el = document.getElementById("div"+id);
    el.style.display="block";
}