var mnuSelected = '';
function showMenu(menu){
hideMenu(mnuSelected);
document.getElementById(menu).style.visibility = 'visible';
mnuSelected = menu;
}
function hideMenu(menu){
if(mnuSelected!='')
document.getElementById(menu).style.visibility = 'hidden';
}


function getElementByClass(a_sClassName)
{
oElements = window.document.getElementsByTagName('*');
aRet = new Array();

for (i=0; i<oElements.length; i++) {
if (oElements[i].className == a_sClassName) {
aRet[aRet.length] = oElements[i];
}
}

return aRet;
}
function init(){
//determine window width
if (window.innerWidth){
	winwidth = window.innerWidth
}else if (document.all){
	winwidth = document.body.clientWidth
}
if (winwidth > 750){
	left = Math.round((winwidth - 750)/2);
}else{
	left = 10
}

//set style.left for menuTrigger items  
mT = getElementByClass("menuTrigger");
for (i=0; i<mT.length; i++){
	mT[i].style.left = left;
}

//set style.left for menu items  
m = getElementByClass("menu");
for (i=0; i<m.length; i++){
	m[i].style.left = left + 120;
}

document.getElementById('mnuBoerderij').style.top =
document.getElementById('Boerderij').style.top;
document.getElementById('mnuDieren').style.top =
document.getElementById('Dieren').style.top;
document.getElementById('mnuPlanten').style.top =
document.getElementById('Planten').style.top;
document.getElementById('mnuWerk').style.top =
document.getElementById('Werk').style.top;
document.getElementById('mnuDagboek').style.top =
document.getElementById('Dagboek').style.top;
}