//Функции общего назначения

function unhide(id){changeDisplayElem(id, "reverse");}
function ChangeVisibilityDiv(id){changeDisplayElem(id, "reverse");}//для старого кода в "autos"
function changeDisplayElem(id){changeDisplayElem(id, "reverse");}
function changeDisplayElem(id, divStatus){//divStatus - "reverse", "on", "off"

  var elm=document.getElementById(id);
  if(elm && elm.className)//Саша мог добавить к элементу класс "hidden" или "unhidden", например: <div id="div2" class="hidden">
  {
   elm.className=(divStatus=="on" || (divStatus=="reverse" && elm.className=='hidden')) ? 'unhidden' : 'hidden';
   return;
  }

  if(!checkExistenceElem(id)){alert("Ошибка!\r\nid="+id+" не существует!");return;}

  var modern = (document.getElementById)? true : false; var nn4 = (document.layers)? true : false; var ie4 = (!modern && document.all)? true : false;
  if(modern||ie4) {
  if(!modern)elm=document.all[id];
  //if(divStatus=="off" || (divStatus=="reverse" && elm.style.visibility == "visible")){elm.style.visibility = "hidden";elm.style.position="absolute";}
  //else if(divStatus=="on" || (divStatus=="reverse" && elm.style.visibility == "hidden")){elm.style.visibility = "visible";elm.style.position="static";}
  if(divStatus=="off" || (divStatus=="reverse" && elm.style.display != "none")){elm.style.display="none";}
  else if(divStatus=="on" || (divStatus=="reverse" && elm.style.display == "none")){elm.style.display="";}
 }
 else if(nn4)
 {elm=document.layers[id]; if(elm.visibility == "show")elm.visibility = "hide"; else elm.visibility = "show";}
}

function checkExistenceElem(id) {
 //var modern = (document.getElementById)? true : false; var nn4 = (document.layers)? true : false; var ie4 = (!modern && document.all)? true : false;
 //if(modern){if(!document.getElementById(id)) return false;}
 //else if(ie4){if(!document.all[id]) return false;} else if(nn4){if(!document.layers[id]) return false;}
 //return true;
 return getElementByIdMur(id)!=null;
}

function getElementByIdMur(id)
{
 var modern = (document.getElementById)? true : false; var nn4 = (document.layers)? true : false; var ie4 = (!modern && document.all)? true : false;
 if(modern)return document.getElementById(id); else if(ie4) return document.all[id];
 else if(document.layers[id])return document.layers[id];
 else return null;
}