function nav(navDiv,triggerDiv)
{	
	if(document.getElementById(triggerDiv).innerHTML == "+")
	{
		document.getElementById(triggerDiv).innerHTML = " - ";
		document.getElementById(navDiv).style.height = "auto";
		document.getElementById(navDiv).style.visibility = "visible";
	}
	else
	{
		document.getElementById(triggerDiv).innerHTML = "+";
		document.getElementById(navDiv).style.height = "0px";
		document.getElementById(navDiv).style.visibility = "hidden";
	}
	return false;
}