function bodysize(grote)
{
var cookiewaarde = xgetCookie('grote');
if (cookiewaarde == '' || cookiewaarde == null ) {
cookiewaarde = 10/10;
}

switch(grote) {
case "=" :
cookiewaarde = parseFloat(cookiewaarde);
break;
case "-" :
cookiewaarde = parseFloat(cookiewaarde) - parseFloat(stap);
break;
case "+" :
cookiewaarde = parseFloat(cookiewaarde) + parseFloat(stap);
break;
default :
cookiewaarde = parseFloat(grote);
}
fontsizeof(document.body,cookiewaarde);
xsetCookie('grote',cookiewaarde);
}

function fontsizeof(oObject,grote) {
if (oObject) {
oObject.style.fontSize = grote + 'em';
}
}

function xsetCookie(name,value) {
//document.cookie = name + "=" + value + ";";
document.cookie = name + '=' + value + '; expires=Thu, 2 Aug 2020 20:47:11 UTC; path=/'
}

function xgetCookie(name) {
//Haal de waardes van een specieke cookie op
var dc = document.cookie;
var prefix = name + "=";
var begin = dc.indexOf("; " + prefix);
if (begin == -1) {
begin = dc.indexOf(prefix);
if (begin != 0) return null;
}
else {
begin += 2;
}
var end = document.cookie.indexOf(";", begin);
if (end == -1) end = dc.length;

return unescape(dc.substring(begin + prefix.length, end));
}










function setActiveStyleSheet(title) {
var i, a, main;
for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) {
a.disabled = true;
if(a.getAttribute("title") == title) a.disabled = false;
}
}
fixswitchknoppen(title);
}

function getActiveStyleSheet() {
var i, a;
for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title") && !a.disabled) return a.getAttribute("title");
}
return null;
}

function getPreferredStyleSheet() {
var i, a;
for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
if(a.getAttribute("rel").indexOf("style") != -1
&& a.getAttribute("rel").indexOf("alt") == -1
&& a.getAttribute("title")
) return a.getAttribute("title");
}
return null;
}

function createCookie(name,value,days) {
if (days) {
var date = new Date();
date.setTime(date.getTime()+(days*24*60*60*1000));
var expires = "; expires="+date.toGMTString();
}
else expires = "";
document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
var nameEQ = name + "=";
var ca = document.cookie.split(';');
for(var i=0;i < ca.length;i++) {
var c = ca[i];
while (c.charAt(0)==' ') c = c.substring(1,c.length);
if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
}
return null;
}

window.onload = function(e) {
var cookie = readCookie("style");
var title = cookie ? cookie : getPreferredStyleSheet();
setActiveStyleSheet(title);
fixswitchknoppen(title);
}

window.onunload = function(e) {
var title = getActiveStyleSheet();
createCookie("style", title, 365);
}

var cookie = readCookie("style");
var title = cookie ? cookie : getPreferredStyleSheet();
setActiveStyleSheet(title);



function fixswitchknoppen(title) {
if(title == "Zwart Wit") {
if(document.getElementById('zwartwit')) document.getElementById('zwartwit').style.display = "none";
if(document.getElementById('kleuren')) document.getElementById('kleuren').style.display = "inline";

}
else {
if(document.getElementById('kleuren')) document.getElementById('kleuren').style.display = "none";
if(document.getElementById('zwartwit')) document.getElementById('zwartwit').style.display = "inline";
}
fixnaartopknop();
}

function fixnaartopknop() {
var title = getActiveStyleSheet()

if(document.getElementById('naartop')) 
{
if(title == "Zwart Wit") {
document.getElementById('naartop').src = "images/button_naartop_bw.gif"
}
else {
document.getElementById('naartop').src = "images/button_naartop.gif"
}
}
}