function validEmail(email) {
        invalidChars = " /:,;"
        if (email == "") return false
        atPos = email.indexOf("@",1)
        if (atPos == -1) return false
   if (email.indexOf("@",atPos+1) > -1) return false
        periodPos = email.indexOf(".",atPos)
   if (periodPos == -1) return false
   if (periodPos+3 > email.length) return false
        for (i=0; i<invalidChars.length; i++) {
                badChar = invalidChars.charAt(i);
                if (email.indexOf(badChar,0) > -1) return false
                }
        return true
}

function Doit() {
        if (validEmail(document.formpje.email.value)) {
                var co=document.formpje.subscribe.length;
                for (ii=0;ii<co;ii++) if (document.formpje.subscribe[ii].checked==true) var sub=document.formpje.subscribe[ii].value;
                url='/myinclude/e_nieuwsbrief_pop.php?sub='+sub+'&email='+document.formpje.email.value
                winStats='toolbar=no,menubar=no,status=no,scrollbars=yes,resizable=yes,width=280,height=260'
                if (screen.width == 1024) {L='220';H='112';}
                else {L='115';H='0';}
                if (navigator.appName.indexOf('Microsoft')>=0) winStats+=',left='+L+',top='+H
                else winStats+=',screenX='+L+',screenY='+H
                hup=window.open(url,'a1',winStats)
                }
        else {
                alert("Sorry, onverwerkbaar e-mailadres!");
                return false;
                }
}