var request = null;

function createRequest() {
  try {
    request = new XMLHttpRequest();
  } catch (trymicrosoft) {
    try {
       request = new ActiveXObject("Msxml2.XMLHTTP");
    }  catch (othermicrosoft) {
       try {
          request = new ActiveXObjects("Microsoft.XMLHTTP");
       }  catch (failed) {
          request = null;
       }
     }   
   }
   if (request == null)
      alert("Nie udało się utworzyć obiektu żądania!");
   else {
      if(request.overrideMimeType){ 
          request.overrideMimeType('text/html; charset=utf-8');
      }  
   }     
}

function get_content(menu,pozycja,lang) {
    createRequest();
    var url = "wybor_ajax.php";

    var obj = document.getElementById('loading');
    if (obj) {
 	   var objStyle = document.getElementById('loading').style;
 	   if (objStyle) {
		 	objStyle.display = 'block'; 
	   }
	} 
	     
    request.onreadystatechange = updatePage;
    request.open("POST", url, true);
    request.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
    if(pozycja != null){
       request.send('sel='+menu+'&poz='+pozycja+'&lang='+lang);
    }else{
       request.send('sel='+menu+'&lang='+lang);
    }
}

function updatePage(){
    if(request.readyState == 4){
      if(request.status ==200){
            var newContent = request.responseText;
            document.getElementById("srodek_txt").innerHTML = newContent;
        } else {
        alert('Wystąpił problem z zapytaniem!');
        }
        
        var obj = document.getElementById('loading');
        if (obj) {
 	       var objStyle = document.getElementById('loading').style;
 	       if (objStyle) {
		      	objStyle.display = 'none'; 
	       }
	    } 
        
        
        
    }
}