function LTrim( value ) {
	var re = /\s*((\S+\s*)*)/;
	return value.replace(re, "$1");
}

function RTrim( value ) {
	var re = /((\s*\S+)*)\s*/;
	return value.replace(re, "$1");	
}

function trim( value ) {
	return LTrim(RTrim(value));
}

window.onload=show;
function show(id) {
var d = document.getElementById(id);
	for (var i = 1; i<=10; i++) {
		if (document.getElementById('smenu'+i)) {document.getElementById('smenu'+i).style.display='none';}
	}
}

function checkContactForm(){
	var emailcheck=/^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;

	var form = document.Contactformulier;
	var alert_msg = '';
	
	if(trim(form.contact_naam.value) == ''){
		alert_msg = alert_msg+'- Naam\n';
	}
	
	if(trim(form.contact_emailadres.value) == ''){
		alert_msg = alert_msg+'- E-mailadres\n';
	}
	else if(!emailcheck.test(form.contact_emailadres.value)){
		alert_msg = alert_msg+'- Geldig e-mailadres\n';	
	}
	
	if(trim(form.contact_onderwerp.value) == ''){
		alert_msg = alert_msg+'- Onderwerp\n';
	}
	
	if(trim(form.contact_bericht.value) == ''){
		alert_msg = alert_msg+'- Bericht\n';
	}

	if(alert_msg != ''){
		alert_msg = 'Wilt u de volgende velden nog invullen:\n\n'+alert_msg;
		alert(alert_msg);
		return;
	}
	
	document.Contactformulier.submit();
	
}