function validateInformatiepakket(formName)
{
    if (document.forms[formName].back.value == 1) {
        return true;
    } else {
        var isValid = true;

        //voorletters
        if (trim(document.forms[formName].prsosltr.value) == '') {
            document.forms[formName].prsosltr.className = 'tb smallwt error';
            document.getElementById('error_prsosltr').className = 'formItem';
            isValid = false;
        } else {
            document.forms[formName].prsosltr.className = 'tb smallwt';
            document.getElementById('error_prsosltr').className = 'hide';
        }

        //achternaam
        if (trim(document.forms[formName].prsnm.value) == '') {
            document.forms[formName].prsnm.className = 'tb error';
            document.getElementById('error_prsnm').className = 'formItem';
            isValid = false;
        } else {
            document.forms[formName].prsnm.className = 'tb';
            document.getElementById('error_prsnm').className = 'hide';
        }

        //geboortedatum
        document.forms[formName].prsdtgeb.value = trim(document.forms[formName].day.value) + '/' + trim(document.forms[formName].month.value) + '/' + trim(document.forms[formName].year.value);
        if (!checkDate(trim(document.forms[formName].day.value), trim(document.forms[formName].month.value), trim(document.forms[formName].year.value))) {
            document.forms[formName].year.className = 'tb year error';
            document.forms[formName].month.className = 'tb month error';
            document.forms[formName].day.className = 'tb date error';
            document.getElementById('error_prsdtgeb').className = 'formItem';
            isValid = false;
        } else if (!isOlder(MAXAGE, trim(document.forms[formName].year.value) + "-" + trim(document.forms[formName].month.value) + "-" + trim(document.forms[formName].day.value))) {
            document.forms[formName].year.className = 'tb year error';
            document.forms[formName].month.className = 'tb month error';
            document.forms[formName].day.className = 'tb date error';
            document.getElementById('error_prsdtgeb').className = 'formItem';
            isValid = false;
        } else {
            document.forms[formName].year.className = 'tb year';
            document.forms[formName].month.className = 'tb month';
            document.forms[formName].day.className = 'tb date';
            document.getElementById('error_prsdtgeb').className = 'hide';
        }

        //geslacht
        if(!document.forms[formName].prslgman[0].checked && !document.forms[formName].prslgman[1].checked) {
            document.getElementById('error_prslgman').className = 'formItem';
            isValid = false;
        } else {
            document.getElementById('error_prslgman').className = 'hide';
        }

        //huisnummer
        if (!trim(document.forms[formName].adphn.value).match(huisnummerExpression)) {
            document.forms[formName].adphn.className = 'tb smallwt error';
            document.getElementById('error_adphn').className = 'formItem';
            isValid = false;
        } else {
            document.forms[formName].adphn.className = 'tb smallwt';
            document.getElementById('error_adphn').className = 'hide';
        }

        //postcode
        if ((document.forms[formName].lndnm.options[document.forms[formName].lndnm.selectedIndex].value).match(/^.*_Nederland$/) && !trim(document.forms[formName].adppk.value).match(postcodeDutchExpression)) {
            document.forms[formName].adppk.className = 'tb smallwt error';
            document.getElementById('error_adppk').className = 'formItem';
            isValid = false;
        } else {
            document.forms[formName].adppk.className = 'tb smallwt';
            document.getElementById('error_adppk').className = 'hide';
        }

        //straat
        if (trim(document.forms[formName].strnm.value) == '') {
            document.forms[formName].strnm.className = 'tb error';
            document.getElementById('error_strnm').className = 'formItem';
            isValid = false;
        } else {
            document.forms[formName].strnm.className = 'tb';
            document.getElementById('error_strnm').className = 'hide';
        }

        //woonplaats
        if (trim(document.forms[formName].pltnm.value) == '') {
            document.forms[formName].pltnm.className = 'tb error';
            document.getElementById('error_pltnm').className = 'formItem';
            isValid = false;
        } else {
            document.forms[formName].pltnm.className = 'tb';
            document.getElementById('error_pltnm').className = 'hide';
        }

        //land
        if (document.forms[formName].lndnm.options[document.forms[formName].lndnm.selectedIndex].value == '') {
            document.getElementById('error_lndnm').className = 'formItem';
            isValid = false;
        } else {
            document.getElementById('error_lndnm').className = 'hide';
        }

        //telefoon
        if (trim(document.forms[formName].adptnpri.value) != '' && !trim(document.forms[formName].adptnpri.value).match(dutchphoneExpression)) {
            document.forms[formName].adptnpri.className = 'tb error';
            document.getElementById('error_adptnpri').className = 'formItem';
            isValid = false;
        } else {
            document.forms[formName].adptnpri.className = 'tb';
            document.getElementById('error_adptnpri').className = 'hide';
        }

        //e-mailadres
        if (document.forms[formName].prskdeml.value != '' && !document.forms[formName].prskdeml.value.match(emailExpression)) {
            document.forms[formName].prskdeml.className = 'tb error';
            document.getElementById('error_prskdeml').className = 'formItem';
            isValid = false;
        } else {
            document.forms[formName].prskdeml.className = 'tb';
            document.getElementById('error_prskdeml').className = 'hide';
        }

        if (document.forms[formName].adptnpri.value == '' || !trim(document.forms[formName].adptnpri.value).match(dutchphoneExpression)) {
            document.forms[formName].adptnpri.className = 'tb error';
            document.getElementById('error_adptnpri').className = 'formItem';
            isValid = false;
        } else {
            document.forms[formName].adptnpri.className = 'tb';
            document.getElementById('error_adptnpri').className = 'hide';
        }

        if (!isValid) {
            document.getElementById('message').className = 'message';
            return false;
        } else {
            document.getElementById('message').className = 'hide';
            return true;
        }
    }
}