var current = "";
		function changeColor(obj){
				current = obj.id;
				//reset all buttons
				resetAll();
				//change color current button
				obj.className = "menukop_on";	
				//reset all submenu's
				resetSubs();
				//show current submenu
				var subname = "submenu_" + obj.id;
				var submenu = document.getElementById(subname);
				if(submenu) {
					submenu.style.display='';
				}	
		}
		
		
		function resetAll(){
			document.getElementById('organisatie').className = "menukop";
			document.getElementById('woningaanbod').className = "menukop";
			document.getElementById('bog').className = "menukop";
			document.getElementById('diensten').className = "menukop";
			document.getElementById('service').className = "menukop";
			document.getElementById('contact').className = "menukop";
		
		}
		function resetSubs(){
			document.getElementById('submenu_organisatie').style.display = 'none';
			document.getElementById('submenu_woningaanbod').style.display = 'none';
			document.getElementById('submenu_bog').style.display = 'none';
			document.getElementById('submenu_diensten').style.display = 'none';
			document.getElementById('submenu_service').style.display = 'none';
			document.getElementById('submenu_contact').style.display = 'none';
		
		}