sfHover = function() {
	var sfEls = document.getElementById("nav").getElementsByTagName("LI");
	for (var i=0; i<sfEls.length; i++) {
		sfEls[i].onmouseover=function() {
			this.className+=" sfhover";
		}
		sfEls[i].onmouseout=function() {
			this.className=this.className.replace(new RegExp(" sfhover\\b"), "");
		}
	}
}
if (window.attachEvent) window.attachEvent("onload", sfHover);


function getUrlVars() {
	
	var map = {};
	var parts = window.location.href.replace(/[?&]+([^=&]+)=([^&]*)/gi, function(m,key,value) {
	map[key] = value;
	});
	
	return map;

}

function wijzigImpressie(nummer){

	var getVariables = getUrlVars();

	if(getVariables['stad']){
	
		var stad = getVariables['stad'];

	}
	else{
	
		var stad = 'den_haag';
	
	}

	afbeelding = document.getElementById('impression_klein');
	afbeelding.src = 'images/projecten/'+stad+'/image_small_'+nummer+'.jpg';
	
	link = document.getElementById('impression_link');
	link.href = 'images/projecten/'+stad+'/image_'+nummer+'.jpg';

}