function open_window(url, title, width, height) {
	lview = window.open(url,title,'toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=yes,resizable=no,width=' + width + ',height=' + height);
	lview.focus();
}
	
function check_email(emailad) {
	var exclude=/[^@\-\.\w]|^[_@\.\-]|[\._\-]{2}|[@\.]{2}|(@)[^@]*\1/;
	var check=/@[\w\-]+\./;
	var checkend=/\.[a-zA-Z]{2,3}$/;
	if(((emailad.search(exclude) != -1)||(emailad.search(check)) == -1)||(emailad.search(checkend) == -1)) {
		alert("Het opgegeven e-mail adres is onjuist, controleer het adres en probeer het opnieuw.");
		return false;
	}
	return true;
}

function MM_showHideLayers() { //v3.0
	var i,p,v,obj,args=MM_showHideLayers.arguments;
	for (i=0; i<(args.length-2); i+=3) if ((obj=MM_findObj(args[i]))!=null) { v=args[i+2];
	if (obj.style) { obj=obj.style; v=(v=='show')?'visible':(v='hide')?'hidden':v; }
	obj.visibility=v; }
}
	
function MM_findObj(n, d) { //v3.0
	var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
	d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
	if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
	for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document); return x;
}
	
function show_button(button) {
	MM_showHideLayers(
		'button_contact_on','','hide',
		'button_algemene_info_on','','hide',
		'button_rdba_on','','hide',
		'button_consultants_on','','hide',
		'button_referenties_on','','hide',
		'button_contact_off','','show',
		'button_algemene_info_off','','show',
		'button_rdba_off','','show',
		'button_consultants_off','','show',
		'button_referenties_off','','show');
	if (button != '') {
		MM_showHideLayers(button,'','show');
	}
}
/*
if (document.all) {
   window.onresize = function (evt) { location.reload(); };
}*/