function makeRequest(obj, divId, url, exec){  
  
	try{    // Firefox, Opera 8.0+, Safari    
		obj=new XMLHttpRequest();   
	}catch (e){    // Internet Explorer    
		try{      
			obj=new ActiveXObject("Msxml2.XMLHTTP");      
		}catch (e){      
			try{        
				obj=new ActiveXObject("Microsoft.XMLHTTP");        
			}catch (e){        
				alert("Your browser does not support AJAX!");   
				return false;     
			}    
		}    
	}
			   
	obj.onreadystatechange=function(){
		if (obj.readyState == 1)
			document.getElementById(divId).innerHTML = "Por favor, aguarde...";
		else if (obj.readyState == 4) {
			if (obj.status == 200) {
				document.getElementById(divId).innerHTML = obj.responseText;
				if(exec != 0){
					if(n_media){
						atualiza_media();
						apaga_estrelas();
					}
					else{
						apaga_estrelas();
					}
				}
				return obj.responseText;
			}else {
				document.getElementById(divId).innerHTML = '<font color="red">Erro de comunicação</font>' + obj.status + ' ' + url;			
			}
		}
	}
	
 	obj.open("GET",url,true);
	obj.send(null);  
}