if (window.attachEvent) {window.attachEvent('onload', pageIsLoaded);}
else if (window.addEventListener) {window.addEventListener('load', pageIsLoaded, false);}
else {document.addEventListener('load', pageIsLoaded, false);} 

function pageIsLoaded() {
	//syntax: het eerste element in de array is de checkbox, de rest zijn de field die verborgen of laten zien moeten worden
	
	//identiteit
	addElements(new Array('cf_field_3','li--4','li--4items','li--5')); //logo ontwerp
	addElements(new Array('cf_field_6','li--7')); //huisstijl ontwerp
	addElements(new Array('cf_field_8','li--9','li--10')); //gevelreclame
	
	//internet
	addElements(new Array('cf_field_12','li--13','li--13items','li--14','li--14items','li--15','li--16','li--16items','li--17','li--18')); //website ontwerp
	addElements(new Array('cf_field_19','li--20','li--20items','li--21','li--21items','li--22','li--23')); //webshop
	addElements(new Array('cf_field_24','li--25','li--26')); //zoekmachine optimalisatie
	addElements(new Array('cf_field_27','li--28','li--28items','li--29','li--29items','li--30','li--30items','li--31')); //e-mail marketing
	addElements(new Array('cf_field_32','li--33','li--33items','li--34','li--35')); //hosting en domeinnamen
	
	//drukwerk
	addElements(new Array('cf_field_37','li--38','li--39','li--40','li--40items','li--43')); //ontwerp brochure
			addElements(new Array('cf_field_40-1','li--41','li--42')); //ontwerp brochure inclusief drukken
			addElements_hide(new Array('cf_field_40-2','li--41','li--42')); //ontwerp brochure inclusief drukken verbergen
	addElements(new Array('cf_field_44','li--45','li--46','li--46items','li--47','li--47items','li--50')); //ontwerp flyer
			addElements(new Array('cf_field_47-1','li--48','li--49')); //ontwerp flyer inclusief drukken
			addElements_hide(new Array('cf_field_47-2','li--48','li--49')); //ontwerp flyer inclusief drukken verbergen
	addElements(new Array('cf_field_51','li--52','li--53','li--53items','li--56')); //ontwerp poster
			addElements(new Array('cf_field_53-1','li--54','li--55')); //ontwerp poster inclusief drukken
			addElements_hide(new Array('cf_field_53-2','li--54','li--55')); //ontwerp poster inclusief drukken verbergen
	addElements(new Array('cf_field_57','li--58','li--58items','li--59','li--59items','li--62')); //ontwerp visitekaartjes
			addElements(new Array('cf_field_59-1','li--60','li--61')); //ontwerp visitekaartjes inclusief drukken
			addElements_hide(new Array('cf_field_59-2','li--60','li--61')); //ontwerp visitekaartjes inclusief drukken verbergen
	addElements(new Array('cf_field_63','li--64','li--64items','li--65','li--65items','li--68')); //ontwerp briefpapier
			addElements(new Array('cf_field_65-1','li--66','li--67')); //ontwerp briefpapier inclusief drukken
			addElements_hide(new Array('cf_field_65-2','li--66','li--67')); //ontwerp briefpapier inclusief drukken verbergen
	addElements(new Array('cf_field_69','li--70','li--71','li--72')); //ontwerp advertenties
	addElements(new Array('cf_field_73','li--74')); //overig grafisch ontwerp
}

function addElements(elements) {
	hideElements(elements);
	addEvents(elements);
}

function hideElements(elements) {
	for(i=1;i<elements.length;i++) {
		document.getElementById(elements[i]).style.display="none";
	}
}

function addEvents(elements) {
	document.getElementById(elements[0]).onclick=function() {
		for(i=1;i<elements.length;i++) {
			if(this.checked) {
				document.getElementById(elements[i]).style.display="";
			} else {
				document.getElementById(elements[i]).style.display="none";
			}
		}
	}
}

//extra functionaliteiten voor het verbergen van items als je ergens op klikt (ja/nee radio button)
function addElements_hide(elements) {
	hideElements(elements);
	addEvents_hide(elements);
}

function addEvents_hide(elements) {
	document.getElementById(elements[0]).onclick=function() {
		for(i=1;i<elements.length;i++) {
			if(this.checked) {
				document.getElementById(elements[i]).style.display="none";
			} else {
				document.getElementById(elements[i]).style.display="";
			}
		}
	}
}