function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		Worldmap12_01_Europe_over = newImage("../images/Worldmap12_01-Europe_over.gif");
		Worldmap12_01_North___America_over = newImage("../images/Worldmap12_01-North---Ameri.gif");
		Worldmap12_01_Australia_over = newImage("../images/Worldmap12_01-Australia_ove.gif");
		Worldmap12_01_Asia_over = newImage("../images/Worldmap12_01-Asia_over.gif");
		Worldmap12_01_South_America_over = newImage("../images/Worldmap12_01-South-America.gif");
		Worldmap12_01_Africa_over = newImage("../images/Worldmap12_01-Africa_over.gif");
		basis_01_ImageMap_04_over = newImage("images/basis_01-ImageMap_04_over.gif");
		basis_01_ImageMap_05_over = newImage("images/basis_01-ImageMap_05_over.gif");
		basis_01_ImageMap_06_over = newImage("images/basis_01-ImageMap_06_over.gif");
		basis_01_ImageMap_07_over = newImage("images/basis_01-ImageMap_07_over.gif");
		basis_01_ImageMap_01_over = newImage("images/basis_01-ImageMap_01_over.gif");
		basis_01_ImageMap_02_over = newImage("images/basis_01-ImageMap_02_over.gif");
		basis_01_ImageMap_03_over = newImage("images/basis_01-ImageMap_03_over.gif");
		basis_engels_01_ImageMap_01_over = newImage("images/basis_engels_01-ImageMap_01.gif");
		basis_engels_01_ImageMap_02_over = newImage("images/basis_engels_01-ImageMap_02.gif");
		basis_engels_01_ImageMap_03_over = newImage("images/basis_engels_01-ImageMap_03.gif");
		basis_engels_01_ImageMap_04_over = newImage("images/basis_engels_01-ImageMap_04.gif");
		basis_engels_01_ImageMap_05_over = newImage("images/basis_engels_01-ImageMap_05.gif");
		basis_engels_01_ImageMap_06_over = newImage("images/basis_engels_01-ImageMap_06.gif");
		basis_engels_01_ImageMap_07_over = newImage("images/basis_engels_01-ImageMap_07.gif");
		preloadFlag = true;
	}
}

function ge(id) {
	return document.getElementById(id);
}

function dataToForm(d) {
	
	opener.ge('vriendexcel').value = d;
	window.close();
	
}

function hideExcel() {
	ge('excelblok').style.display = 'none';
}

function showExcel() {
	ge('excelblok').style.display = 'block';
}

function showNextPage(showid, hideid) {
	ge(showid).style.display = 'block';
	ge(hideid).style.display = 'none';
}

function showNextFriend(id) {
	ge(id).style.display = 'block';
}

var oudpag = 1;

function showNextPag (pag, totaal) {
	
	if (oudpag) {
		ge('zoekpag' + oudpag).style.display = 'none';
		ge('zoekpagnr' + oudpag).className = 'zoekpagnr';
	}
	
	ge('zoekpag' + pag).style.display = 'block';
	ge('zoekpagnr' + pag).className = 'zoekpagnractief';
	
	oudpag = pag;
	
}

function showNext(totaal) {
		
		if ((oudpag + 1) <= totaal) {
			
			var nextpag = (oudpag + 1);
			
			ge('zoekpag' + oudpag).style.display = 'none';
			ge('zoekpagnr' + oudpag).className = 'zoekpagnr';
			
			ge('zoekpag' + nextpag).style.display = 'block';
			ge('zoekpagnr' + nextpag).className = 'zoekpagnractief';
			
			oudpag = nextpag;
			
		}
		
}

function showPrev (totaal) {
		
		if ((oudpag - 1) > 0) {
			
			var prevpag = (oudpag - 1);
			
			ge('zoekpag' + oudpag).style.display = 'none';
			ge('zoekpagnr' + oudpag).className = 'zoekpagnr';
			
			ge('zoekpag' + prevpag).style.display = 'block';
			ge('zoekpagnr' + prevpag).className = 'zoekpagnractief';
			
			oudpag = prevpag;
			
		}
		
}

function changeAnswer (leesverder_txt, txt, taal, leesverder) {
	
	var htmltxt = txt;
	if (leesverder) {
		htmltxt += "<a href='?pag=" + leesverder + "' class='knop'>";
		htmltxt += " <nobr><img src='img/knop/pijl_volgende.gif' alt='' style='padding-top: 5px;'> ";
		htmltxt += leesverder_txt;
		htmltxt += "</nobr></a>";
	}
	
	ge('homeuitleg').innerHTML = htmltxt;
	
}

function changeTotals () {
	
	/* update rij1 */
	rij1total = parseInt(document.forms['freken'].land1baat.value) + parseInt(document.forms['freken'].land2baat.value) + parseInt(document.forms['freken'].land3baat.value);
	ge('rij1').innerHTML = rij1total;
	
	/* update rij2 */
	rij2total = parseInt(document.forms['freken'].land1last.value) + parseInt(document.forms['freken'].land2last.value) + parseInt(document.forms['freken'].land3last.value);
	ge('rij2').innerHTML = rij2total;
	
	/* update col1 */
	col1total = parseInt(document.forms['freken'].land1baat.value) - parseInt(document.forms['freken'].land1last.value);
	ge('col1').innerHTML = col1total;
	
	/* update col2 */
	col2total = parseInt(document.forms['freken'].land2baat.value) - parseInt(document.forms['freken'].land2last.value);
	ge('col2').innerHTML = col2total;
	
	/* update col3 */
	col3total = parseInt(document.forms['freken'].land3baat.value) - parseInt(document.forms['freken'].land3last.value);
	ge('col3').innerHTML = col3total;
	
	/* update total */
	ge('grtotal').innerHTML = rij1total - rij2total;

}