var tab, start=false, og_h, og_s;

var plus=20;//10;
var interval=2.3;//3;

function menu(t,s){
	t.href="#";
	og_s=s;
	
	req("_tab.php?x="+s,ok);
	
	//v ie to ide pomaly,, ie je shit
	if (navigator.appName=="Microsoft Internet Explorer"){
		zobraz_m(false);
		return;
	}
	
	if (!start)
		start=true;
	else
		return;
	
	tab=null;
	
	var tmp=document.getElementsByTagName("div");
	for (var n in tmp)
		if (tmp[n].className=="obsah_menu"){
			tab=tmp[n];
			break;
		}
		
	if (tab==null){
		zobraz_m(false);
		return;
	}
		
	tab.style.overflow="hidden";
	og_h=tab.clientHeight;

	for (var i=100;i>=0;i-=plus)
		setTimeout("fade("+i+",true)",Math.round((1+Math.abs(i-100))*interval));
}

function zobraz_m(anim){
	var s=og_s;
	for (var i=0;i<4;i++){
		o=(i==s);
		document.getElementById("zal_"+i).className=(o?"zal_zobraz":"zal_skryt");
		document.getElementById("m_"+i+"_0").className="z_vlavo"+(o?"_s":"");
		document.getElementById("m_"+i+"_1").className="z_stred"+(o?"_s":"");
		document.getElementById("m_"+i+"_2").className="z_vpravo"+(o?"_s":"");
	}
	
	if (anim){
		tab.style.height="";
		tab.style.overflow="visible";
		og_h=tab.clientHeight;
	
		tab.style.height="0px";
		tab.style.overflow="hidden";
	
		for (var i=0;i<=100;i+=plus)
			setTimeout("fade("+i+",false)",Math.round((1+i)*interval));
	}else{
		start=false;
	}
	//fade(100,false);
}

function fade(b,x){
	try{
		tab.style.opacity=tab.style.MozOpacity=tab.style.KhtmlOpacity=b/100;
		tab.style.filter="alpha(opacity="+b+")";
		
		tab.style.height=Math.floor(og_h/100*b)+"px";
		if (x){
			if (b==0)
				zobraz_m(true);
		}else if (b==100){
			tab.style.height="";
			tab.style.overflow="visible";
			start=false;
		}
	}catch (e){
	}
}

function ok(a){}

function rx(){
	if (!window.XMLHttpRequest){
 		try{ return new ActiveXObject("MSXML3.XMLHTTP") }catch(e){}
    try{ return new ActiveXObject("MSXML2.XMLHTTP.3.0") }catch(e){}
    try{ return new ActiveXObject("Msxml2.XMLHTTP") }catch(e){}
    try{ return new ActiveXObject("Microsoft.XMLHTTP") }catch(e){}
    throw new Error("Could not find an XMLHttpRequest alternative.")
  }else{
  	return new XMLHttpRequest();
  }
}

function req(url,c){
	var request=rx();
	if (request==null)
		return false;
	
  request.open("GET",url,true);
  request.setRequestHeader("Content-Type","application/x-www-form-urlencoded"); 
  request.onreadystatechange=function(){
  	
  	if (request.readyState==4 && request.status==200){
    	if (request.responseText)
      	c(request.responseText);
   	}
  };
  request.send("");
  return true;
}