//added by Twee-D on 27 march 2008
// TvW: for 'inschrijven'
function showlayer(layer) {
	var myLayer = document.getElementById(layer).style.display;
	if(myLayer=="none"){
		document.getElementById(layer).style.display="block";
	} else {
		document.getElementById(layer).style.display="none";
	}
}
// TvW: for 'inschrijven'
function validateForm() {
    var fouten;
    fouten='';

    if (document.forms[0].firstname.value==0) {
        fouten+='- Voornaam\n';
    }
    if (document.forms[0].surname.value==0) {
        fouten+='- Achternaam\n';
    }
    if (document.forms[0].phone.value==0) {
        fouten+='- Telefoon\n';
    }

        // uitgebreidde email check
        if (document.forms[0].email.value==0)
        {
        fouten+='- E-mail\n';
        }
        else {
            var email_check = document.forms[0].email.value;
            //adjusted by Twee-D on 27 march 2008 - added the requirement that a domain needs at least 2 characters
            var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-]{2,100})+\.)+([a-zA-Z0-9]{2,4})+$/;
            if (filter.test(email_check));
            else fouten+='- E-mail is incorrect\n';
        }

    if (document.forms[0].study.value==0) {
        fouten+='- Studie\n';
    }
    if (!document.forms[0].education_type[0].checked && !document.forms[0].education_type[1].checked) {
        fouten+='- Soort onderwijs\n';
    }

    if (fouten!='') {
        // errors gevonden!
        alert('Sommige verplichte velden ontbreken!\nKlik OK en vul de ontbrekende velden correct in:\n\n'+fouten);
        return false
    }
}

// TvW: for 'inschrijven'

function addEvent(obj, evt, func){
	if(obj.addEventListener){
		obj.addEventListener(evt,func,false);
	}
	else if(obj.attachEvent){
		obj.attachEvent("on"+evt,func);
	}
	else {
		obj["on"+ evt] = func;
	}
}

function checkMail(mail){
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (filter.test(mail)) 
		return true;
	return false;
}

function checkFormData()
{
	var submiterror = 0;
	inputTags = document.getElementById('send_mail_form').getElementsByTagName('input');
	textAreas = document.getElementById('send_mail_form').getElementsByTagName('textarea');
	spans = document.getElementById('send_mail_form').getElementsByTagName('span');
	for(i=0;i<spans.length;i++)
		spans[i].innerHTML='';	

	for(i=0;i<inputTags.length;i++){
		error_element = "error_"+inputTags[i].name;
		if ((inputTags[i].value == "" || typeof inputTags[i].value == 'undefined') && inputTags[i].getAttribute('type') != 'hidden' && inputTags[i].getAttribute('type')!='submit') {		
			document.getElementById(error_element).innerHTML = 'U bent vergeten dit veld in te vullen.';
			submiterror++;
		}
		if (inputTags[i].name == 'emailadres' && !checkMail(inputTags[i].value)){
			document.getElementById(error_element).innerHTML = 'Ongeldig e-mailadres';
			submiterror++;
		}
	}
	
	for(i=0;i<textAreas.length;i++){
		error_element = "error_"+textAreas[i].name;
		if (textAreas[i].value == "" || typeof textAreas[i].value == 'undefined'){
			document.getElementById(error_element).innerHTML = 'U bent vergeten een vraag in te vullen';
			submiterror++;
		}
	}		
	if (submiterror >0)
		return false;
	return true;
}

function initFormCheck(){
	alert('test');
	addEvent(document.getElementById('send_mail_form'), 'submit', function(){return checkFormData();});
}

//addEvent(window, 'load', initFormCheck);