function changevisibility(obj) {
  var object = document.getElementById(obj);
  if (object.style.display == 'block') {
          object.style.display = 'none';
  } else {
          object.style.display = 'block';
  }
}

function doajax(){
	var xmlhttp=false;
	/* for IE...*/
	try {
		xmlhttp = new ActiveXObject('Msxml2.XMLHTTP');
	}
	catch(e) {
		try{
			xmlhttp = new ActiveXObject('Microsoft.XMLHTTP');
		}
		catch(E){
			xmlhttp = false;
		}
	}
	/* for Mozilla...*/
	if(!xmlhttp && typeof XMLHttpRequest!='undefined'){
		xmlhttp = new XMLHttpRequest();
	}
	return xmlhttp;
}

function showDistricts(id_department){
	var request=doajax();
	if(request){
		request.onreadystatechange=function(){
			if(request.readyState==4){
				var destiny=document.getElementById("districts2");
				var controls=document.getElementById("districts1");
				destiny.innerHTML=request.responseText;
				destiny.style.display="block";
				controls.style.display="none";
			}
		}
		request.open("GET", "districts.php?department="+id_department, true);
		request.send(null);
	}else{
		alert("El objeto httprequest no se pudo crear.");
	}
}
function showDistricts2(id_department, domain){
	var request=doajax();
	if(request){
		request.onreadystatechange=function(){
			if(request.readyState==4){
				var destiny=document.getElementById("districts2");
				var controls=document.getElementById("districts1");
				destiny.innerHTML=request.responseText;
				destiny.style.display="block";
				controls.style.display="none";
			}
		}
		request.open("GET", domain+"/districts2.php?department="+id_department, true);
		request.send(null);
	}else{
		alert("El objeto httprequest no se pudo crear.");
	}
}

function showSections(laboratory, category, domain, group){
	var request=doajax();
	if(request){
		request.onreadystatechange=function(){
			if(request.readyState==4){
				var destiny=document.getElementById("choose-2");
				var controls=document.getElementById("choose-1");
				destiny.innerHTML=request.responseText;
				destiny.style.display="block";
				controls.style.display="none";
			}
		}
		request.open("GET", domain+"/sections.php?cat="+category+"&grp="+group+"&laboratory="+laboratory, true);
		request.send(null);
	}else{
		alert("El objeto httprequest no se pudo crear.");
	}
}