function tab_set_active( elt ) {
	var tabs_elt = $("tabs");
	if (tabs_elt) {
		var tabs = my_getElementsByClass( "tab", tabs_elt)
		for (var t=0;t<tabs.length;t++){
			t_elt = tabs[t];
			if (t_elt) {
				t_elt.className = (elt==t_elt ? "tab active" : "tab");
				if (elt==t_elt) {
					inhoud = my_getElementsByClass("tab_inhoud", t_elt);
					if (inhoud) {
						$("tabs_content").innerHTML = inhoud[0].innerHTML;
					}
				}
			}
		}
	}
}

function tab_set_first_active() {
	var tab_req = (window.location.hash!="" ? window.location.hash.substring(window.location.hash.indexOf('#tab=')+5, window.location.hash.length) : "");
	var cur_tab = 0;
	
	if (tab_req!="") {
		cur_tab = parseInt( tab_req ) - 1;
	}
	var tabs_elt = $("tabs");
	if (tabs_elt) {
		var tabs = my_getElementsByClass( "tab", tabs_elt);
		if (tabs) { tab_set_active(tabs[cur_tab]) } 
	}
}

function init_page() {
	// somehow the right elements needs to be reset on ie6 and ie7
	var x = $("rechts");
	if (x) { x.style.top = 113; x.style.overflow="hidden"; }
}


// 	 Retrieves an array of DOM elements by Classname
//
function my_getElementsByClass(searchClass,node,tag) {
	var classElements = new Array();
	if (node == null) node = document;
	if (tag == null) tag = '*';
	var els = node.getElementsByTagName(tag);
	var elsLen = els.length;
	var pattern = new RegExp("(^|\\s)"+searchClass+"(\\s|$)");
	for (i = 0, j = 0; i < elsLen; i++) {
		if (pattern.test(els[i].className)) {
			classElements[j] = els[i];
			j++;
		}
	}
	return classElements;
}