var temp = "";
	
	function showMenu(menu) {
		var menuLink = document.getElementById('link_' + menu);
		var menuTab = document.getElementById('tab_' + menu);
		
		var tabs = document.getElementsByTagName('div');
		var links = document.getElementsByTagName('a');

		// resetten van alle tabs en links
		
		for (i=0; i< tabs.length; i++) {
			var aTab = tabs[i];
			if (aTab.className == 'blok') {
				aTab.style.display = '';
			}
		}
				
		// nieuw tab en link zetten
		if (menuTab.style.display == '') {
			menuTab.style.display = 'block';
		} else {
			menuTab.style.display = '';
		}
		
	// einde showmenu
	}