function limit() {
var frm = document.getElementById('formulier');


if (frm.elements['opmerkingen'].value.length > 165) {
	frm.elements['opmerkingen'].value=frm.elements['opmerkingen'].value.substr(0,165);

	}
}

function isNumberKey(evt)
{
	var charCode = (evt.which) ? evt.which : event.keyCode
	if (charCode > 31 && (charCode < 48 || charCode > 57))
	return false;
	return true;
}

function alpha(e)
{
	var k;
	document.all ? k = e.keyCode : k = e.which;
	return ((k > 64 && k < 91) || (k > 96 && k < 123) || k == 8);
}

function frmsubmit()
{
	var frm = document.getElementById('formulier');
	
	var voornaam = frm.elements['voornaam'].value;
	var achternaam = frm.elements['achternaam'].value;
	var email = frm.elements['email'].value;
	var straat = frm.elements['straat'].value;
	var postcode1 = frm.elements['postcode1'].value;
	var postcode2 = frm.elements['postcode2'].value;
	var plaats = frm.elements['plaats'].value;
	
	var mssg = '';
	
	if (voornaam == '') { mssg += 'Voornaam\n'; }
	if (achternaam == '') { mssg += 'Achternaam\n'; }
	if (!check_email(email)) { mssg += 'Geldig e-mail adres\n'; }
	if (straat == '') { mssg += 'Straat\n'; }
	if (postcode1 == '' || postcode2 == '') { mssg += 'Postcode\n'; }
	if (plaats == '') { mssg += 'Plaats\n'; }
	
	
	if (mssg)
	{
		var error = 'De volgende velden zijn verplicht:\n\n';
		alert(error+mssg);
		return false;
	}
	else
	{
		frm.submit();
	}
		
}

function check_email(address)
{
    var emailPat=/^(.+)@(.+)$/;
    var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]";
    var validChars="\[^\\s" + specialChars + "\]";
    var quotedUser="(\"[^\"]*\")";
    var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;
    var atom=validChars + '+';
    var word="(" + atom + "|" + quotedUser + ")";
    var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
    var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");
    var matchArray=address.match(emailPat);
	
    if (matchArray==null) { 
		return false;
	}
	
    var user=matchArray[1];
    var domain=matchArray[2];

    if (user.match(userPat)==null) {
        return false;
    }

    var IPArray=domain.match(ipDomainPat)
    	if (IPArray!=null) {
          for (var i=1;i<=4;i++) {
            if (IPArray[i]>255) {
                return false;
            }
        }
        return true;
    }

    var domainArray=domain.match(domainPat);
    if (domainArray==null) {
        alert("De ingevulde domeinnaam is ongeldig.")
        return false
    }

    var atomPat=new RegExp(atom,"g");
    var domArr=domain.match(atomPat);
    var len=domArr.length;
    if (domArr[domArr.length-1].length<2 ||
        domArr[domArr.length-1].length>4) {
       return false;
    }

    if (len<2) {
       return false;
    }
    return true;
}