function showvis (id){ 
    if (document.getElementById) { 
        obj = document.getElementById(id);
        if (obj.style.visibility == "visible") { 
            obj.style.visibility = "hidden"; 
        } else { 
            obj.style.visibility = "visible"; 
        }
    }
}
function showhide (id){
    if (document.getElementById) {
        obj = document.getElementById(id);
        if (obj.style.display == "block") {
            obj.style.display = "none";
        } else {
            obj.style.display = "block";
        }
    }
}
function showmenu (id){ 
    if (document.getElementById) { 
        obj = document.getElementById(id);
        if (obj.style.visibility == "hidden") { 
            obj.style.visibility = "visible"; 
        }
    }
}

function hidemenu (id){ 
    if (document.getElementById) { 
        obj = document.getElementById(id);
        if (obj.style.visibility == "visible") { 
            obj.style.visibility = "hidden"; 
        }
    }
}
function block (id){
    if (document.getElementById) {
        obj = document.getElementById(id);
        obj.style.display = "block";
    }
}
function none (id){
    if (document.getElementById) {
        obj = document.getElementById(id);
        obj.style.display = "none";
    }
}