var wlclosetime = 500;
var wlcurrentmenu = 0;
var wltimer = 0;

function open_window_centred(win_url, win_name, win_w, win_h, styles)
{
  var win_left = (screen.width - win_w) / 2;
  var win_top = (screen.height - win_h) / 2;
  
  var win_style = (styles == undefined)? '' : styles + ', ';
  
  win_style += 'width=' + win_w;
  win_style += ',height=' + win_h;
  win_style += ',left=' + win_left;
  win_style += ',top=' + win_top;

  var newwin = window.open(win_url, win_name, win_style);
  newwin.focus();
  return;
}

function wlshowmenu(newmenu){
  wlcancelclose();
  if(wlcurrentmenu) wlcurrentmenu.style.display = 'none';
  wlcurrentmenu = document.getElementById(newmenu);
  wlcurrentmenu.style.display = 'block';
 wlcurrentmenu.style.visibility = 'visible';
}
function wlclosefinal(){
  wlcurrentmenu.style.display = 'none';
   wlcurrentmenu.style.visibility = 'hidden';
}

function wlclosemenu(newmenu){
    wlcurrentmenu = document.getElementById(newmenu);
    wltimer = window.setTimeout(wlclosefinal, wlclosetime );
  //alert(newmenu);

}



function wlcancelclose(){
 window.clearTimeout(wltimer);
 wltimer= null;
}