function vytvorAjax(){
var xmlHttp;
try{
  xmlHttp=new XMLHttpRequest(); // Firefox, Opera 8.0+, Safari
  return xmlHttp;
}catch (e){
  	try{  // Internet Explorer
    	xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
		return xmlHttp;
    }catch (e){
    	try{
      		xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
			return xmlHttp;
      	}catch (e){
      		alert("Vas staroveky prehliadac nepodporuje AJAX!");
      		return false;
      	}
    }
}

}

function nacitaj(limit){
	var limit="limit="+limit;
	xxx = vytvorAjax();
	xxx.onreadystatechange=function(){
		if(xxx.readyState==4){
			document.getElementById("stred").innerHTML = xxx.responseText;
			document.body.style.cursor = "default";
		}else{
			document.body.style.cursor = "wait";
		}
	}
	xxx.open("POST","chat/nacitaj.php",true);
	xxx.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");                  
	xxx.send(limit);
}
function posli(){
	var nick = encodeURIComponent(document.getElementById("nick").value);
	var text = encodeURIComponent(document.getElementById("text").value);
	var mail = encodeURIComponent(document.getElementById("mail").value);
	var captcha = document.getElementById("captcha").value;
	var data = "nick="+nick+"&text="+text+"&mail="+mail+"&captcha="+captcha;
	zzz = vytvorAjax();
	zzz.onreadystatechange=function(){
		if(zzz.readyState==4){
			if(zzz.responseText.substring(0,5)!="CHYBA") {
				document.getElementById("text").value="";
			}
			alert(zzz.responseText);
			nacitaj(0);
			document.body.style.cursor = "default";
		}else{
			document.body.style.cursor = "wait";
		}
	}
	zzz.open("POST","chat/posli.php",true);
	zzz.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");                  
	zzz.send(data);
}

function mailingList(){
	var mail = document.getElementById("mailingList").value;
	var data = "mail="+mail;
	mmm = vytvorAjax();
	mmm.onreadystatechange=function(){
		if(mmm.readyState==4){
			if(mmm.responseText.substring(0,5)!="CHYBA") {
				document.getElementById("mailingList").value="";
			}
			alert(mmm.responseText);
			document.body.style.cursor = "default";
		}else{
			document.body.style.cursor = "wait";
		}
	}
	mmm.open("POST",SITE+"/mailingList.php",true);
	mmm.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	mmm.send(data);
}