function getScreen() {
  var myWidth = 0, myHeight = 0;
  if( typeof(document.body.innerWidth ) == 'number' ) {
    //Non-IE
    myWidth = document.body.innerWidth;
    myHeight = document.body.innerHeight;
  } else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
    //IE 6+ in 'standards compliant mode'
    myWidth = document.documentElement.clientWidth;
    myHeight = document.documentElement.clientHeight;
  } else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
    //IE 4 compatible
    myWidth = document.body.clientWidth;
    myHeight = document.body.clientHeight;
  }
  return [myWidth, myHeight];
  
}

function setBackground() {
 	var a = getScreen();
	var myWidth = a[0], myHeight = a[1];
  	//window.alert( 'Width = ' + myWidth );
 	//window.alert( 'Height = ' + myHeight );
 
	bg_width = (myWidth * 1.00);
	bg_height = (myHeight * 1.00);
	
	var NewWidth = bg_width;
 	var NewHeight = Math.round(NewWidth * .267);
	
	if (document.getElementById) {
	
		if (myWidth>1000 && document.getElementById("the_header_image")) {
			document.getElementById("the_header_image").width = NewWidth;
			document.getElementById("the_header_image").height = NewHeight;
			
		}
	}
}

function changecss(theClass,element,value) {
	//Last Updated on June 23, 2009
	//documentation for this script at
	//http://www.shawnolson.net/a/503/altering-css-class-attributes-with-javascript.html
	var cssRules;

	var added = false;
	for (var S = 0; S < document.styleSheets.length; S++){

    if (document.styleSheets[S]['rules']) {
	  cssRules = 'rules';
	 } else if (document.styleSheets[S]['cssRules']) {
		 cssRules = 'cssRules';
	 } else {
	  //no rules found... browser unknown
	 }

	 for (var R = 0; R < document.styleSheets[S][cssRules].length; R++) {
	   if (document.styleSheets[S][cssRules][R].selectorText == theClass) {
	    if(document.styleSheets[S][cssRules][R].style[element]){
	    document.styleSheets[S][cssRules][R].style[element] = value;
	    added=true;
		break;
		}
	   }
	 }                                                                                      
	 
	 if(!added){
	  if(document.styleSheets[S].insertRule){
			document.styleSheets[S].insertRule(theClass+' { '+element+': '+value+'; }',document.styleSheets[S][cssRules].length);
			} else if (document.styleSheets[S].addRule) {
				document.styleSheets[S].addRule(theClass,element+': '+value+';');
			}
	 	 }  
	 }
}

/* preload images function */
var preloaded = new Array();

function preload_images() {
    for (var i = 0; i < arguments.length; i++){
        preloaded[i] = document.createElement('img');
        preloaded[i].setAttribute('src',arguments[i]);
    };
};

function removeClasses() {
	$('#menulink_overons').removeClass('active');
	$('#menulink_klantspecifiek').removeClass('active');
	$('#menulink_standaard').removeClass('active');
	$('#menulink_overig').removeClass('active');
	$('#menulink_contact').removeClass('active');
	//hide submenus
	$('#list_overons').hide();
	$('#list_klantspecifiek').hide();
	$('#list_standaard').hide();
	$('#list_overig').hide();
	$('#list_contact').hide();
}

function checkSubmenu(){
	
	$('.closed').show('slide', { direction: 'up' }, 400);  
	$('#submenu').removeClass('closed');
	$('#submenu').addClass('opened');
}

function closeSubmenu(){    
	removeClasses();
	$('.opened').hide('slide', { direction: 'up' }, 500);  
	$('.active').fadeOut('slow');
	$('#submenu').removeClass('opened');
	$('#submenu').addClass('closed');	
}