function displaycontent(id) {
 if(id != null){
    var d = document.getElementById(id).style.display;
    document.getElementById(id).style.display = (d == "none" || d == "") ? "block" : "none";
    if(document.getElementById(id).style.display == "none"){
        document.getElementById("divopen").style.display = "block";
        document.getElementById("divclose").style.display = "none";
        }
    else
        {
        document.getElementById("divopen").style.display = "none";
        document.getElementById("divclose").style.display = "block";
        }
    }
 }

var cur = '';
function show(id){
    document.getElementById(id).style.display = "block";
    cur = id;
}
function hide(){
    if(cur != '') document.getElementById(cur).style.display = "none";
}