puo andare bene un esempio cosi?

ho cercato di farlo in modo semplice con delle funzioni che si possono riusare.

Codice PHP:
<html> 
    <head> 
        <title>aste</title> 
        <SCRIPT LANGUAGE="JavaScript"> 
            var indicefocus=0; 
            function isChecked(elemento,indice) 
            { 
                var mycheck=false; 
                for (i = 0; i < elemento.length; i++) 
                { 
                    if(elemento[i].checked) 
                    { 
                        mycheck=true; 
                    } 
                }             
                if(!mycheck) 
                { 
                    indicefocus=indice; 
                    alert("Non hai compilato la domanda numero "+indicefocus); 
                } 
                return mycheck; 
            } 
            function controllocampi() 
            { 
                errore=false; 
                for (indice = 1; indice <=2; indice++) 
                { 
                    if(!isChecked(document.test.elements["domanda"+indice],indice)) 
                    { 
                        errore=true;
                        break; 
                    }       
                }                  
                if(errore) 
                { 
                    document.test.elements["domanda"+indicefocus][0].focus();  
                } 
                else 
                { 
                    alert("ho inviato tutto");                     
                } 
            }              
        </script> 
    </head> 
    <body> 
        <form name="test" id="test" action="javascript:controllocampi();"> 
            DOMANDA 1
 
            <input id="domanda1" name="domanda1" type="checkbox" value="1" />A

            <input id="domanda1" name="domanda1" type="checkbox" value="2" />B

            <input id="domanda1" name="domanda1" type="checkbox" value="3" />C

            <input id="domanda1" name="domanda1" type="checkbox" value="4" />D

            
 
            DOMANDA 2
 
            <input id="domanda2" name="domanda2" type="checkbox" value="1" />A

            <input id="domanda2" name="domanda2" type="checkbox" value="2" />B

            <input id="domanda2" name="domanda2" type="checkbox" value="3" />C

            <input id="domanda2" name="domanda2" type="checkbox" value="4" />D

            
 
            <input type="submit" value="INVIA" />
        </form>
    </body>
</html>