var touched_tab = null;
var active_tab = null;
var tabs = new Array("Unternehmen", "Service", "Aktuell", "Kontakt", "Produkte");


function init_topnavig() {
	for (t in tabs) {
		var tab = document.getElementById("Tabber_tab" + tabs[t]);
		if (tab.className.indexOf("active") != -1) {
			active_tab = tab;
			active_name = tabs[t];
			break;
		}
	}
	
	document.onmousemove = tabber_mmove;
}

function tabber_mmove(e) {
	var src = (e == null || e == "undefined") ? event.srcElement : e.target;
	while (
		src != null &&
		src.tagName != "HTML" &&
		src.className.indexOf("Tabber_tab tab") &&
		src.id != "Tabber_bottom"
	)
		src = src.parentNode;
	
	if (src == null || src.tagName == "HTML") tabber_reset();
	else if (src.className.indexOf("Tabber_tab tab") != -1) tabber_touch(src);
}

function tabber_reset() {
	if (touched_tab == null) return;
	document.getElementById(touched_tab.id + "_bottom").style.display = "none";
	touched_tab.style.backgroundPosition = "0 0";
	touched_tab.style.color = "#0071B8";
	if (active_tab != null) {
		document.getElementById(active_tab.id + "_bottom").style.display = "block";
		active_tab.style.backgroundPosition = tabber_bgpos(active_tab);
		active_tab.style.color = "#0071B8";	
	}
	touched_tab = null;
}

function tabber_touch(tab) {
	if (tab == touched_tab) return;
	if (touched_tab != null) {
		document.getElementById(touched_tab.id + "_bottom").style.display = "none";
		touched_tab.style.backgroundPosition = "0 0";
		touched_tab.style.color = "#0071B8";
	}
	if (active_tab != null) {
		document.getElementById(active_tab.id + "_bottom").style.display = "none";
		active_tab.style.backgroundPosition = tabber_bgpos(active_tab);
		active_tab.style.color = "#0071B8";
	}

	document.getElementById((touched_tab = tab).id + "_bottom").style.display = "block";
	touched_tab.style.backgroundPosition = tabber_bgpos(touched_tab);
	touched_tab.style.color = "#0071B8";
	
}

function tabber_bgpos(tab) {
	return tab.id == "Tabber_tabUnternehmen" ? "0 -27px" : tab.id == "Tabber_tabService" ? "0 -54px" : tab.id == "Tabber_tabAktuell" ? "0 -81px" : tab.id == "Tabber_tabKontakt" ? "0 -108px" :	tab.id == "Tabber_tabProdukte" ? "0 -135px" : "0 0";
}