function showDDNav() {
	args = showDDNav.arguments;
	var divName = args[0];
	var divRef;
	
	if(is.nav && !is.nav6up) {
		divRef = eval("document." + divName);
		if(divRef.visibility == 'hide'){
			divRef.visibility = 'show';
		}
	}
	else {
		if(is.nav6up) {
			divRef = eval("document.getElementById('" + divName + "')");
		}
		else {
			divRef = eval("document.all." + divName);
		}

		if(divRef.style.visibility == 'hidden'){
			divRef.style.visibility = 'visible';
		}
	}
}


function hideDDNav() {
	args = hideDDNav.arguments;
	var divName = args[0];
	var divRef;
	
	if(is.nav && !is.nav6up) {
		divRef = eval("document." + divName);
		if(divRef.visibility == 'show') {
			divRef.visibility = 'hide';
		}
	}
	else {
		if(is.nav6up) {
			divRef = eval("document.getElementById('" + divName + "')");
		}
		else {
			divRef = eval("document.all." + divName);
		}

		if(divRef.style.visibility == 'visible') {
			divRef.style.visibility = 'hidden';
		}
	}
}


function hideDiv() {
	args = hideDiv.arguments;
	var divName = args[0];
	var divRef;

	// fix menu flicker problem in IE
	if(is.ie) {
		divRef = eval("document.all." + divName);

		// calculate active size of menu
		leftDiv = divRef.offsetLeft + 2
		rightDiv = divRef.offsetLeft + divRef.clientWidth - 2
		topDiv = divRef.offsetTop + 2
		bottomDiv = divRef.offsetTop + divRef.clientHeight - 2

		if(window.event.clientY > bottomDiv || window.event.clientY < topDiv || window.event.clientX < leftDiv || window.event.clientX > rightDiv) {
			divRef.style.visibility = 'hidden';
		}
	}
	else {
		// NS6
		divRef = eval("document.getElementById('" + divName + "')");
		divRef.style.visibility = 'hidden';
	}
}