function switchElement(str, element, newval) {
	var first, second, secondstart, index;
	if(str.indexOf(element) > 0) {
		first = str.substring(0, str.indexOf(element)+element.length);
		second = str.substring(str.indexOf(element)+element.length + 1, str.length);
		if(second.indexOf("&") > 0) {
			second = second.substring(second.indexOf("&"), second.length);	
		} else {
			second = "";
		}
		str = first + newval + second;
	} else {
		if(str.indexOf("?") > 0) {
			str = str + "&" + element  + newval;
		} else {
			str = str + "?" + element  + newval;		
		}	
	}
	return str;
}

function reloadMenu(lvl1, lvl2, lvl3, lvl4, tab) {
	reloader(lvl1, lvl2, lvl3, lvl4, document.location, tab);
}

function reloader(lvl1, lvl2,lvl3, lvl4, dir, tab) {
	if(!lvl1) lvl1 = 0;
	if(!lvl2) lvl2 = 0;
	if(!lvl3) lvl3 = 0;
	if(!lvl4) lvl4 = 0;
	if(!tab) tab = 1;
	var next = "" + dir;
	next = switchElement(next, "level1=", lvl1);
	next = switchElement(next, "level2=", lvl2);
	next = switchElement(next, "level3=", lvl3);
	next = switchElement(next, "level4=", lvl4);		
	next = switchElement(next, "menutab=", tab);
	document.location = next;
}

function show(obj) {
	if(obj) {
		if(document.getElementById) {
			document.getElementById(obj).style.display = "block";
		}
		else if(document.all) {
			document.all[obj].style.display = "block";
		}
		else if(document.layers) {
			document.layers[obj].visibility = "show";
		}
	}
}

function hide(obj) {
	if(obj) {
		if(document.getElementById){
			document.getElementById(obj).style.display = "none";
		}
		else if(document.all) {
			document.all[obj].style.display = "none";
		}
		else if(document.layers) {
			document.layers[obj].visibility = "hidden";
		}
	}
}

function isShowing(obj) {
	if(document.getElementById){
		return (document.getElementById(obj).style.display=="block");
	}
	else if(document.all) {
		return (document.all[obj].style.display=="block");
	}
	else if(document.layers) {
		return (document.layers[obj].visibility=="show");
	}
}

function toggle(obj, lvl1, lvl2, lvl3, lvl4, tab, imagename) {
	if(document.layers) {
		reloadMenu(lvl1, lvl2, lvl3, lvl4, tab);
	} else if(isShowing(obj)) {
		hide(obj);
	}
	else {
		show(obj);
	}	
}