function objRef(id) {if (document.getElementById(id)) return document.getElementById(id)}
function styleRef(id) {return this.objRef(id).style}

function hl(obj){
           b=obj.src;
           s=(b.substring(b.length-4,b.length-5)==0)?'1':'0';
           obj.src=(b.substring(b.length-5,0)+s+b.substring(b.length,b.length-4));
}	


/* 
	getViewportSize: geeft grootte van browservenster in array [w,h]
	Zorgt voor workaround van IE bug (IE clientWidth kijkt naar grootte van document, niet naar venster!)
	bron: http://blog.stchur.com/2006/09/06/the-ie-resize-bug-revisited/ 
*/
function getViewportSize() {
    var size = [0, 0];
    if (typeof window.innerWidth != 'undefined') {
    	size = [ window.innerWidth, window.innerHeight ];
    }
    else if (typeof document.documentElement != 'undefined' && 
             typeof document.documentElement.clientWidth != 'undefined' &&
             document.documentElement.clientWidth != 0)
    {
    	size = [ document.documentElement.clientWidth, document.documentElement.clientHeight ];
    }
    else
    {
    	size = [ document.getElementsByTagName('body')[0].clientWidth, document.getElementsByTagName('body')[0].clientHeight ];
    }
    return size;
}	


/*
 *  Aanpassen van kantlijnen wanneer schermbreedte beneden 1016 pixels komt
 */
function doResize(){
	var windowWidth, minSiteWidth, newWidth, currentSize;
	minSiteWidth = 970;
	currentSize = getViewportSize();
	windowWidth = currentSize[0];
	
	/* set gray border width */
	newWidth = 1016;
	if (windowWidth<1016){
		if (windowWidth>minSiteWidth) {newWidth=windowWidth;} else {newWidth=minSiteWidth;}
	}
	objRef('siteContainerGrayBorder').style.width = newWidth+'px';
	
	/* set white border width */
	newWidth = 1000;
	if (windowWidth<1000){
		if (windowWidth>minSiteWidth) {newWidth=windowWidth;} else {newWidth=minSiteWidth;}
	}
	objRef('siteContainerWhiteBorder').style.width = newWidth+'px';
	
	/* debug: breedte afbeelden */
	/* 
		objRef('siteContainer').innerHTML = '<br><br><br>schermbreedte = ' + windowWidth + ' (bug in IE, is nooit kleiner dan 1016)<br>getviewport = '+ currentSize[0]; 
	*/
}


/*
 *  Afbeelden van klok rechtsboven		
 */
function displayClock() {
	var mydate=new Date();
	var year=mydate.getYear();
	if (year < 1000) year+=1900;
	var day=mydate.getDay();
	var month=mydate.getMonth();
	var daym=mydate.getDate();
	var hour=mydate.getHours();
	var min=mydate.getMinutes();
	if (min <10) min="0" + min; 
	if (daym<10) daym="0" + daym;
	var dayarray=new Array("ZO","MA","DI","WO","DO","VR","ZA");
	var montharray=new Array("JANUARI","FEBRUARI","MAART","APRIL","MEI","JUNI","JULI","AUGUSTUS","SEPTEMBER","OKTOBER","NOVEMBER","DECEMBER");
	var display = dayarray[day] + " " + daym + " " + montharray[month] + ' | ' + hour + ":" + min;
	objRef('clock').innerHTML = display;
}


/*
 *  Show/hide het juiste submenu bij het klikken op een van de 3 hoofdmenu buttons
 */
function menuClick(nr){
	var k, state;
	for (k=1;k<=3;k++){ 
		if (k==nr) {state = 'block';} else {state = 'none';}
		objRef('submenu'+k).style.display = state;
	}
	/*
	objRef('submenu1').style.display = 'none';
	objRef('submenu2').style.display = 'none';
	objRef('submenu3').style.display = 'none';
	*/
	
}


/*
 *	Uitvoeren wanneer pagina geladen is
 */
function onLoadHandler(){
	displayClock(); /* Display clock eenmaal */
	doResize();		/* Pas evt. kantlijnen aan */
}



setInterval("displayClock()", 60000); /* eens per minuut */
window.onresize = doResize;