function obj_on(obj){
  if(document.getElementById(obj)){
    el = document.getElementById(obj)
    el.style.display = 'block'
  }
}
function obj_off(obj){
  if(document.getElementById(obj)){
    el = document.getElementById(obj)
    el.style.display = 'none'
  }
}
function obj_swap(obj){
  if(document.getElementById(obj)){
    el = document.getElementById(obj)
    if(el.style.display == 'none' || el.style.display == ''){
      el.style.display = 'block'
    } else {
      el.style.display = 'none'
    }
  }
}


function mark_menu(obj){
  if(document.getElementById(obj)){
    el = document.getElementById(obj);
    el.style.color = 'yellow';
  }
}


function mark_cat(obj){
  if(document.getElementById(obj)){
    el = document.getElementById(obj);
    el.style.fontWeight = 'bold';
  }
}


function pause(ms){
  var nw, gt;
  nw = new Date();
  gt = nw.getTime() + ms;
  while (nw.getTime() < gt) {
    nw = new Date();
  }
}


function goBack(){
  if (history.length > 0){
  	history.back()
  }
}
function MM_goToURL() { //v3.0
  var i, args=MM_goToURL.arguments; document.MM_returnValue = false;
  for (i=0; i<(args.length-1); i+=2) eval(args[i]+".location='"+args[i+1]+"'");
}