//hides corresponding div
    function hide(divId) {
    if (document.layers) document.layers[divId].visibility = 'hide';
    else if (document.all) document.all[divId].style.visibility = 'hidden';
    else if (document.getElementById) document.getElementById(divId).style.visibility = 'hidden';
    }

    //shows corresponding div
    function show(divId) {
    if (document.layers) document.layers[divId].visibility = 'show';
    else if (document.all) document.all[divId].style.visibility = 'visible';
    else if (document.getElementById) document.getElementById(divId).style.visibility = 'visible';
    }