var timeout	= 100; // msec
var timer = 0;
var prevopened = 0;

// open sub menu
function MenuOpen(id) {
  // clear menu close timeout
  CloseCancel();
  // close previous opened menu
  if(prevopened) { prevopened.style.visibility = 'hidden'; }
  // open new sub menu
  prevopened = document.getElementById(id);
  prevopened.style.visibility = 'visible';
}

// close sub menu
function MenuClosing() {
  timer = window.setTimeout(MenuClose, timeout);
}

// close sub menu
function MenuClose() {
  if(prevopened) { prevopened.style.visibility = 'hidden'; }
}

// clear menu close timeout
function CloseCancel() {
  if(timer) {
    window.clearTimeout(timer);
    timer = 0;
  }
}

// close layer when click-out
document.onclick = MenuClose; 


//contents show and hide
function exSw(contid) {
  if (document.getElementById) {
  	if (document.getElementById(contid).style.display == "block") {
  		document.getElementById(contid).style.display = "none";
  	} else {
  		document.getElementById(contid).style.display = "block"
  	}
  }
}