var timer, i, menuId, submenuId;

var dom = document.getElementById ? true : false;
var ie4 = ((document.all) && (!dom)) ? true : false;
var ns4 = document.layers ? true : false;
var opera = navigator.userAgent.indexOf('Opera') != -1 ? true : false;
var dhtml = dom ? true : ie4 ? true : ns4 ? true : false;

var submenus=3;

function setBGColor(id,color) {
  if (dhtml)
  {
    if (dom) document.getElementById(id).style.backgroundColor = color;
    else if (ie4) document.all[id].style.backgroundColor = color;
    else if (ns4) eval('id.' + element + '.backgroundColor = color');
  }
}

function setVisibility(element,newVisibility)
{
  if (dhtml)
  {
    if (dom) document.getElementById(element).style.visibility = newVisibility;
    else if (ie4) document.all[element].style.visibility = newVisibility;
    else if (ns4) eval('document.' + element + '.visibility = newVisibility');
  }
}

function timedHideMenu(id,smid)
{
    setVisibility(smid,'hidden')
}

function showMenu(id)
{
  if (dhtml)
  {
    clearTimeout(timer);
    for (i = 1; i <= submenus; i++) if (i != id) {
	    	menuId=(ns4 ? 'document.' : '') + 'menu' + i;
	    	submenuId=(ns4 ? 'document.' : '') + 'submenu' + i;
	    	timedHideMenu(menuId,submenuId);
	    }
    setVisibility((ns4 ? 'document.' : '') + 'submenu' + id,'visible');
    
  }
}

function hideMenu(id)
{
  if (dhtml)
  {
    menuId = (ns4 ? 'document.' : '') + 'menu' + id;
    submenuId = (ns4 ? 'document.' : '') + 'submenu' + id;
    timer = setTimeout("timedHideMenu(menuId,submenuId)",250);
  }
}

function dontHideMenu(id)
{
  if (dhtml) {
	  clearTimeout(timer);
    	}
}


function SwapImg(name,img)
{
	eval('document.' + name + '.src = "' + img + '"');
}

function okno(co,sir,vys) {
fotografie = window.open(co+"","","resizeable=no,toolbar=no,status=no,menubar=no,scrollbars=no,directories=no,location=no,resize=no,width="+sir+",height="+vys+"");
vyska = screen.height;
sirka = screen.width;
var levy = (sirka - sir)/2;
var horni = (vyska - vys)/2;
fotografie.moveTo(levy, horni);
}