var canSwitch = false;
if (parseInt(navigator.appVersion) >= 5 && navigator.appName != "Opera" || navigator.userAgent.indexOf("MSIE") != -1) {
    canSwitch = true;
}

plus = new Image();     plus.src = "images/plus.gif";
minus = new Image();    minus.src = "images/minus.gif";

function hide(kat, imgname){
if(canSwitch){
  var podmenu;
  podmenu = document.getElementById(kat);
  if(podmenu && podmenu.style) podmenu.style.display = 'none';
  eval("document."+imgname+".src=plus.src");
}
}

function show(kat, imgname){
if(canSwitch){
  var podmenu;
  podmenu = document.getElementById(kat);
  podmenu.style.display='block';
  eval("document."+imgname+".src=minus.src");
}
}

function switch2(kat, imgname){
if(canSwitch){
  var podmenu;
  podmenu = document.getElementById(kat);
  var visible = (podmenu.style.display!='none');
  if(visible){
      podmenu.style.display='none';
	  eval("document."+imgname+".src=plus.src");
  }else{
      podmenu.style.display='block';
	  eval("document."+imgname+".src=minus.src");
  }
}
return false;
}