function verify() {
    //alert("checking...");
    var themessage = "De volgende velden zijn verplicht:  \n";
    var ok =true;
    if (document.form.location.value=="") {
        themessage = themessage + " - Locatie\n";
        ok =false;
    }
    if (document.form.name.value=="") {
        themessage = themessage + " - Uw naam\n";
        ok = false;
    }
    if (document.form.code.value=="") {
        themessage = themessage + " - Bevestig deze code";
        ok = false;
    }
    //alert if fields are empty and cancel form submit

    if (ok) {
        document.form.submit();
    }
    else {
        alert(themessage);
        //return false;
    }
}

function nextField(evt) {
    evt = (evt) ? evt : event;
    var target = (evt.target) ? evt.target : evt.srcElement;
    var form = target.form;
    var charCode = (evt.charCode) ? evt.charCode :((evt.which) ? evt.which : evt.keyCode);
    if (charCode == 13) {
        if (target == document.form.location) document.form.name.focus();
        else if (target == document.form.name) document.form.description.focus();
        //else if (target == document.form.description) document.form.code.focus();
        else verify();
    }
    return true;
}