nn4=(document.layers)?true:false;
ie4=(document.all)?true:false;

function init() {
  if(!nn4 && !ie4) {return;}
  document.onclick = mouseClick;
  if(nn4) {
    document.captureEvents(Event.MOUSECLICK);
  }
}
window.onload=init;

function mouseClick(e) {
  if(nn4) {
    zwin();
  } else if(ie4) {
    if(event.srcElement.parentElement != document.all['belkaDiv']) {
      zwin();
    }
  }
  return true;
}


function zwin() {
		hideLayers('menuDiv1');
		hideLayers('menuDiv2');
		hideLayers('menuDiv3');
		hideLayers('menuDiv4');
}


function hideLayers(menuName) {
	if (nn4) {
		document.layers[menuName].visibility = "hide";
	} else {
		document.all[menuName].style.visibility = "hidden";
	}
}

function popUp(menuName,on) {
		if (nn4) {
			if (document.layers['menuDiv1']) {ok = true;}
			else {ok = false;}
		} else {
			if (document.all['menuDiv1']) {ok = true;}
			else {ok = false;}
		}

		if (ok){
			hideLayers('menuDiv1');
			hideLayers('menuDiv2');
			hideLayers('menuDiv3');
			hideLayers('menuDiv4');
			if (on) {
				if (nn4) {
					document.layers[menuName].visibility = "show";
				} else {
					document.all[menuName].style.visibility = "visible";
				}
			} else {
				if (nn4) {
					document.layers[menuName].visibility = "hide";
				} else {
					document.all[menuName].style.visibility = "hidden";
				}
			}
		}
}